RG1012 核电厂地震仪表 1997.docx

RG1012 核电厂地震仪表 1997.docx

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RG1012核电厂地震仪表1997

Revision2

March1997

RegulatoryGuide1.12

NuclearPowerPlantInstrumentationForEarthquakes

（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