RG1.098 沸水堆中放射活性废气排放系统潜在放射性后果评价所使用的假设 1976

U.S.NUCLEARREGULATORYCOMMISSIONREGULATORYGUIDEOFFICEOFSTANDARDSDEVELOPMENTREGULATORYGUIDE1.98ASSUMPTIONSUSEDFOREVALUATINGTHEPOTENTIALRADIOLOGICALCONSEQUENCESOFARADIOACTIVEOFFGASSYSTEMFAILUREINABOILINGWATERREACTORA.INTRODUCTIONB.DISCUSSIONSection5034,ContentsofApplications:Techni-OffgassystemsofboilingwaterreactorsarecalInformation,of10CFRPart50,LicensingofdesignedtoreducethereleaseofradioactivematerialstoProductionandUtilizationFacilities,requiresthateachtheatmosphere.BothradioactiveandnonradioactiveapplicantforaconstructionpermitoroperatinglicensegasesaredissolvedinthereactorcoolantofboilingwaterprovideananalysisandevaluationofthedesignandreactorsandarereleasedtothesteamInboilingperformanceofstructures,systems,andcomponentsofprocess.TheradioactivegasesareactivatlessuchasthefacilitywiththeobjectiveofassessingtherisktoN-13,N.16,and0-19thatare1ordrolementspublichealthandsafetyresiltingfromoperationofthewhichbecomeradioactiveinpeughactorfacility.GeneralDesignCriterion61,FuelStorageandcorefromtheeffect.ofneutrPýonuchasHandlingandRadioactivityControl,tofAppendixA,thenoblegaseskryptxesefromtheGeneralDesignCriteriaforNuclearPowerPlants,toburnupoffuel.notisesareairthatis10CFRPart50requires,inpart,thatsystemswhichintroducedintoeaccwiththemakeupmaycontainradioactivitybedesignedtoensureade-feedwaterIinturbinecondenserandquatesafetyundernormalandpostulatedaccidenthydrnducedbyradiolyticdecompoconditions.sitoeenonradioactivegasesarebyfarptituentsofgasesinthecoolant.GasesRadioactiveoffgassystemsofboilingwaternuc:ofromthecondensingsteaminthemainpowerreactorsareusedtopermitdecayofradirythesteamjetairejectors(SJAE)andthengasesasameansofreducingthereleaseodi'tivetebytheradioactiveoffgassystem.materialstotheatmosphere.Theaccidleothecontentsfromthissystemisaated'iAseriesofparametricstudies(Ref.1)hasbeenperusedtoevaluatetheadequacyofthesstewithformedtoassesstheradiologicalconsequencesofanoffrespecttothepublichealthandsafet.guidegassystemaccidentbasedonthedosethatanindividualprovidesassumptionsbletotheNRCstaffforlocatedatthesiteboundarywouldreceivefromshortuseinevaluatingthetologicalconsequencesoftermreleaseofthenoblegasesandtheirdaughters,thispostulattiniemecases,unusualsiteactivationgases,iodine,andparticulatematteronthedharactetip1defeatures,orotherfactorshigh-efficiencyparticulateair(HEPA)filters.TheaccimaYreeregassumptionswhichwillbecon-dentpostulatedbythestaffassumesreleaseof100%ofdei,ebasis.thenoblegasinventorystoredinthesystemanda'USNRCREGULATORYGUIDESCommentsshouldbesenttotheSecretaryoftheCommission.U.S.NuclearRegulatoryGuidesaeissuedtodescribeandmakeavailabletothepubticRegulatoryCommission.Washington.D.C.2055.Attention:DocketingandmethodsacceptabletotheNRCstaffofimplementingspecificpartsoftheServiceSection.Commission'sregulations,todelineatetechniquesusedbythestaffinevslu-TheguidespieissuedIthefollowingtenbroaddivisions:stingspecificproblemsorpostulatedaccidents.ortoprovideguidancetoappligcents.RegulatoryGuidesarenotsubstitutestarregulations,andcompliance1.PowerReactorsS.ProductswiththemIsnotrequired.Methodsandsolutionsdifferantfromthosesetoutn2.ResearchandTeatReactors7.Transporationtheguideswinbeacceptableittheyprovideabasisforthefindingsrequisiteto2.FuelsandMaterialsacUtom&OccupationalHealththeissuanceorcontinuanceofapermitorfcensebytheCommission.4,EnvironmentalandSitingse.le.AntitrustReviewCommentsandsuggestionsforimprovementsintheseguidesareencouragedSMaterialsandPlantProtection10.Generalatalltimes,andguideswillberevised,esappropriate,toaccommodateeammentsandtoreflectnewinformationorexperience.However.commentsonCopiesofpublishedguidesmaybeobtainedbywrittenrequestindicatingthethisguide,ifreceivedwithinabouttwomonthsafterItsissuance,willbeper.divisionsdesiredtotheU.S.NuclearRagulatoryCommission.Washington.D.C.titcularlyusefulinevaluatingtheneedforanearlyrevision2O55.Attention:ODiector.OfficeofStandardsDevelopment.March1976/fractionalreleaseoftheparticulatematteronthefilterunderupsetconditionsinvolvingexplosionorfire.AlthoughWASH-1338,insomecases,postulatestotalreleaseofthematerialtrappedontheHEPAfilterlocatedattheendofthedelayline,thisguidedoesnotspecifythefractionalreleaseofparticulatestobeusedandtheapplicantshouldsubstantiatehisselectionofaspecifiedfractionalrelease.Thisfractionalreleasewillbeevaluatedonacase-by-casebasis.WhenmoreinformationpertainingtothefractionalreleaseofparticulatematterfromHEPAfiltersunderupsetconditionsIsavailable,thisguidewillberevisedtoincludeaspecificparticulatereleasefraction.C.REGULATORYPOSITIONI.Theassumptionsrelatedtothereleaseofradioactivematerialfromthefuelare:a.AnoblegasreleaserateattheSJAEsuchthatitwouldequal350,000pCi/secafter30-mindelay,foraperiodof30daysprecedingthepostulatedaccidentandof100,000ACi/sec(at30-mindelay)fortimesearlierthan30daysfora3500MWtreactor.Thereleaserateshouldbescaledlinearlyforreactorsofhigherandlowerpowers.b.TheisotopiccompositionofthenoblegasesmaybedeterminedfromTableI.TABLE1NOBLEGASSOURCETERMSourceTerm,pCi/secApprox.30-Min.IsotopeHalf-Life0DecayDecayXe-14