RG1012 核电厂地震仪表 1997Word格式.docx
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(DraftissuedasDG-1033)
[DivisionIndex|RegulatoryGuideIndex|NRCHomePage]
PublicationInformation
A.INTRODUCTION
In10CFRPart20,"
StandardsforProtectionAgainstRadiation,"
licenseesarerequiredtomakeeveryreasonableefforttomaintainradiationexposuresaslowasisreasonablyachievable.ParagraphIV(a)(4)ofAppendixS,"
EarthquakeEngineeringCriteriaforNuclearPowerPlants,"
to10CFRPart50,"
DomesticLicensingofProductionandUtilizationFacilities,"
requiresthatsuitableinstrumentationmustbeprovidedsothattheseismicresponseofnuclearpowerplantfeaturesimportanttosafetycanbeevaluatedpromptlyafteranearthquake.ParagraphIV(a)(3)ofAppendixSto10CFRPart50requiresshutdownofthenuclearpowerplantifvibratorygroundmotionexceedingthatoftheoperatingbasisearthquakegroundmotion(OBE)occurs.1
ThisguidedescribesseismicinstrumentationthatisacceptabletotheNRCstaffforsatisfyingtherequirementsofPart20andAppendixStoPart50.
Theinformationcollectionscontainedinthisregulatoryguidearecoveredbytherequirementsof10CFRPart50,whichwereapprovedbytheOfficeofManagementandBudget,approvalnumber3150-0011.TheNRCmaynotconductorsponsor,andapersonisnotrequiredtorespondto,acollectionofinformationunlessitdisplaysacurrentlyvalidOMBcontrolnumber.
B.DISCUSSION
Whenanearthquakeoccurs,itisimportanttotakepromptactiontoassesstheeffectsoftheearthquakeatthenuclearpowerplant.Thisassessmentincludesbothanevaluationoftheseismicinstrumentationdataandaplantwalkdown.Solid-statedigitaltime-historyaccelerographsinstalledatappropriatelocationswillprovidetime-historydataontheseismicresponseofthefree-field,containmentstructure,andotherSeismicCategoryIstructures.Theinstrumentationshouldbelocatedsothattheresponsemaybecomparedandevaluatedwiththedesignbasisandsothatoccupationalradiationexposuresassociatedwiththeirlocation,installation,andmaintenancearemaintainedaslowasreasonablyachievable(ALARA).
Instrumentationisprovidedinthefree-fieldandatfoundationlevelandatelevationinSeismicCategoryIstructures.Free-fieldinstrumentationdatawillbeusedtocomparemeasuredresponsetotheengineeringevaluationsusedtodeterminethedesigninputmotiontothestructuresandtodeterminewhethertheOBEhasbeenexceeded(seeRegulatoryGuide1.166).Theinstrumentslocatedatthefoundationlevelandatelevationinthestructuresmeasureresponsesthataretheinputtotheequipmentorpipingandwillbeusedinlong-termevaluations(seeRegulatoryGuide1.167,"
RestartofaNuclearPowerPlantShutDownbyaSeismicEvent"
).Foundation-levelinstrumentationwillprovidedataontheactualseismicinputtothecontainmentandotherSeismicCategoryIstructuresandwillbeusedtoquantifydifferencesbetweenthevibratorygroundmotionatthefree-fieldandatthefoundationlevel.Instrumentationisnotlocatedonequipment,piping,orsupportssinceexperiencehasshownthatdataobtainedattheselocationsareobscuredbythevibratorymotionassociatedwithnormalplantoperation.
TheguidanceinRegulatoryGuide1.166isbasedontheassumptionthatthenuclearpowerplanthasoperableseismicinstrumentation,includingtheequipmentandsoftwareneededtoprocessthedatawithin4hoursafteranearthquake.Thisisnecessarytodeterminewhetherplantshutdownisrequired.ThisdeterminationwillbemadebycomparingtherecordeddataagainstOBEexceedancecriteriaandbyevaluatingtheresultsoftheplantwalkdowninspectionsthattakeplacewithin8hoursoftheevent.
Itmaynotbenecessaryforidenticalnuclearpowerunitsonagivensitetoeachbeprovidedwithseismicinstrumentationifessentiallythesameseismicresponseateachoftheunitsisexpectedfromagivenearthquake.
AnNRCstaffevaluationofseismicinstrumentationnotedthatinstrumentshavebeenoutofserviceduringplantshutdownandsometimesduringplantoperation.Theinstrumentationsystemshouldbeoperableandoperatedatalltimes.IftheseismicinstrumentationordataprocessinghardwareandsoftwarenecessarytodeterminewhethertheOBEhasbeenexceededisinoperable,theguidelinesinAppendixAtoRegulatoryGuide1.166shouldbeused.
Thecharacteristics,installation,activation,remoteindication,andmaintenanceoftheseismicinstrumentationaredescribedinthisguidetohelpensure
(1)thatthedataprovidedarecomparablewiththedatausedinthedesignofthenuclearpowerplant,
(2)thatexceedanceoftheOBEcanbedetermined,and(3)thattheequipmentwillperformasrequired.
Itisimportantthatallthesignificantgroundmotionassociatedwithanearthquakeisrecorded.Thisisaccomplishedbyspecifyinghowlongbeforeandaftertheactuationoftheseismictriggerthedatashouldberecorded.Settingsfortheinstrumentation'
spre-eventmemoryshouldbecorrelatedwiththemaximumdistancetoanypotentialepicenterthatcouldaffectaspecificsite.The"
P"
wavemaynotberecordedwithonlya3-secondmemorysetting.Also,whenaneventoccursatsomedistanceandthetriggerthresholdlimitisnotexceededuntil15or20secondsintotheevent,apartoftherecord,althoughatlowamplitude,islost.A30-secondvaluemaybemoreappropriateandiswithinthecapabilitiesofcurrentdigitaltime-historyaccelerographsatnoadditionalcost.
Theappendixtothisguideprovidesdefinitionstobeusedwiththisguidance.
C.REGULATORYPOSITION
Thetype,locations,operability,characteristics,installation,actuation,remoteindication,andmaintenanceofseismicinstrumentationdescribedbelowareacceptabletotheNRCstaffforsatisfyingtherequirementsin10CFRPart20andParagraphIV(a)(4)ofAppendixSto10CFRPart50forensuringthesafetyofnuclearpowerplants.
1.SEISMICINSTRUMENTATIONTYPEANDLOCATION
1.1Solid-statedigitalinstrumentationthatwillenabletheprocessingofdataattheplantsitewithin4hoursoftheseismiceventshouldbeused.
1.2Atriaxialtime-historyaccelerographshouldbeprovidedatthefollowinglocations:
1.Free-field.
2.Containmentfoundation.
3.Twoelevations(excludingthefoundation)onastructureinsidethecontainment.
4.AnindependentSeismicCategoryIstructurefoundationwheretheresponseisdifferentfromthatofthecontainmentstructure.
5.Anelevation(excludingthefoundation)ontheindependentSeismicCategoryIstructureselectedin4above.
6.Ifseismicisolatorsareused,instrumentationshouldbeplacedonboththerigidandisolatedportionsofthesameoranadjacentstructure,asappropriate,atapproximatelythesameelevations.
1.3ThespecificlocationsforinstrumentationshouldbedeterminedbythenuclearplantdesignertoobtainthemostpertinentinformationconsistentwithmaintainingoccupationalradiationexposuresALARAforthelocation,installation,andmaintenanceofseismicinstrumentation.Ingeneral:
1.3.1Thefree-fieldsensorsshouldbelocatedandinstalledsothattheyrecordthemotionofthegroundsurfaceandsothattheeffectsassociatedwithsurfacefeatures,buildings,andcomponentsontherecordedgroundmotionwillbeinsignificant.
1.3.2Thein-structureinstrumentationshouldbeplacedatlocationsthathavebeenmodeledasmasspointsinthebuildingdynamicanalysissothatthemeasuredmotioncanbedirectlycomparedwiththedesignspectra.Theinstrumentationshouldnotbelocatedonasecondarystructuralframememberthatisnotmodeledasamasspointinthebuildingdynamicmodel.
1.3.3Adesignreviewofthelocation,installation,andmaintenanceofproposedinstrumentationformaintainingexposuresALARAshouldbeperformedbythefacilityintheplanningstageinaccordancewithRegulatoryGuide8.8,"
InformationRelevanttoEnsuringthatOccupationalRadiationExposuresatNuclearPowerStationsWillBeAsLowAsIsReasonablyAchievable."
1.3.4Instrumentationshouldbeplacedinalocationwithaslowadoserateasispractical,consistentwithotherrequirements.
1.3.5Instrumentsshouldbeselectedtorequireminimalmaintenanceandin-serviceinspection,aswellasminimaltimeandnumbersofpersonneltoconductinstallationandmaintenance.
2.INSTRUMENTATIONATMULTI-UNITSITES
Instrumentationinadditiontothatinstalledforasingleunitwillnotberequiredifessentiallythesameseismicresponseisexpectedattheotherunitsbasedontheseismicanalysisusedintheseismicdesignoftheplant.However,ifthereareseparatecontrolrooms,annunciationshouldbeprovidedtobothcontrolroomsasspecifiedinRegulatoryPosition7.
3.SEISMICINSTRUMENTATIONOPERABILITY
Theseismicinstrumentationshouldoperateduringallmodesofplantoperation,includingperiodsofplantshutdown.Themaintenanceandrepairproceduresshouldprovideforkeepingthemaximumnumberofinstrumentsinserviceduringplantoperationandshutdown.
4.INSTRUMENTATIONCHARACTERISTICS
4.1Thedesignshouldincludeprovisionsforin-servicetesting.Theinstrumentsshouldbecapableofperiodicchannelchecksduringnormalplantoperation.
4.2Theinstrumentsshouldhavethecapabilityforin-placefunctionaltesting.
4.3Instrumentationthathassensorslocatedininaccessibleareasshouldcontainprovisionsfordatarecordinginanaccessiblelocation,andtheinstrumentationshouldprovideanexternalremotealarmtoindicateactuation.
4.4Theinstrumentationshouldrecord,ataminimum,3secondsoflow-amplitudemotionpriortoseismictriggeractuation,continuetorecordthemotiond