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| {{#Wiki_filter:QwjwII~~ENGINEERINGSTUDIES,ANALYSES,ANDEVALUATIONSCOVERSHEETOIAI.ITYI.EYEI.AFETYASIDERTIIEDIIOIINAI.ITYED/CTIIND,.SEAIIODcrIID.FADEIOF4yEVALUATIONOFWELDEDSHUTCLASS1ELIMITORQUELIMITSWITCHESUSEDFORUNIT2COMPUTERINP9006290165900619PDRADOCK05000337PPDCOI3ogo,peak~Ill+/y~REVISIONNO.DATEPREPAREDBYI'IoREVIEIEDBYPPROVEDB IEI~'ILA") | | {{#Wiki_filter:QwjwII~~ENGINEERING STUDIES,ANALYSES, ANDEVALUATIONS COVERSHEET OIAI.ITYI.EYEI.AFETYASIDERTIIEDIIOIINAI.ITYED/CTIIND,.SEAIIODcrIID.FADEIOF4yEVALUATION OFWELDEDSHUTCLASS1ELIMITORQUE LIMITSWITCHESUSEDFORUNIT2COMPUTERINP9006290165 900619PDRADOCK05000337PPDCOI3ogo,peak~Ill+/y~REVISIONNO.DATEPREPAREDBYI'IoREVIEIEDBYPPROVEDB IEI~'ILA") |
| SEA-EE-226Page2of6EVALUATIONOFWELDEDSHUTCLASS1ELIMITORQUELIHITSWITCHESUSEDFORUNIT2COMPUTERINPUTS1.0SCOPEThepurposeofthisSEAistoevaluatetheimpactofaweldedshutlimitswitchfromClasslELimitorquemotoroperatorsontheoperationoftheClass1Evalve.SEA-EE-183determinedthatclosedLimitorquecomputerinputlimitswitchescouldweldshutforimpressedvoltagefaults. | | SEA-EE-226 Page2of6EVALUATION OFWELDEDSHUTCLASS1ELIMITORQUE LIHITSWITCHESUSEDFORUNIT2COMPUTERINPUTS1.0SCOPEThepurposeofthisSEAistoevaluatetheimpactofaweldedshutlimitswitchfromClasslELimitorque motoroperators ontheoperation oftheClass1Evalve.SEA-EE-183 determined thatclosedLimitorque computerinputlimitswitchescouldweldshutforimpressed voltagefaults. |
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| ==2.0CONCLUSION== | | ==2.0CONCLUSION== |
| SANDRECOMMENDATIONS
| | S ANDRECOMMENDATIONS |
|
| |
|
| ==2.1CONCLUSION== | | ==2.1CONCLUSION== |
| SAnalysisoftheUnit2ClasslEmotor-operatedvalvesshowsthatthesevalves,exceptforMainSteamLineDrainIsolationValvesHV-821-2F016andHV-821-2F019andtheReactorWaterCleanupIsolationValvesHV-G33-2F001andHV-G33-2F004,willmeettheirminimumperformancerequirementsevenifthecomputerinputlimitswitchesshouldweldshut.Thisconclusionisbaseduponanevaluationthatshows:--Thevalveschangepositionandmeettheirminimumperformancerequirementsbeforethecomputerinputlimitswitchesareexposedtopotentialcontactwelding,i.e.thevalvelimitswitchesarenormallyopenandtheyclosewhenthevalvechangespositiontoitsisolationposition.OR-Thevalvesareinaffiliated(associated)circuitsandcontactsfromthesedevicesarenotusedinClass1Ecircuits,i.e.operationofthevalveisnotrequiredfordesignbasiseventconditions.IntheeventcomputerinputlimitswitchesforHV-G33-2F001,HV-G33-2F004,HV-821-2F016andHV-821-2F019weldshut,thelimitswitchmaindriveshaftscouldperhapsbreaklooseinternaltothevalvescausingthevalvestojam,thuspotentiallypreventingfull.closureofthevalves.Morethanlikelytheweldedshutlimitswitcheswouldcausedamagetothelimitswitchgearing,butwouldnotpreventthesubjectvalvesfromclosing.2.2RECOMMENDATIONToassurethattheHV-G33-2F001,HV-G33-2F004,HV-821-2F016andHV-821-1F019valvesmeettheirminimumperformancerequirementswithimpressedvoltagefaultsontheircomputerinputcables,thecomputerinputlimitswitchesshouldberewiredsuchthatthesevalveschangepositionandmeettheirminimumperformancerequirementsbeforethecomputerinputswitchesareexposedtopotentialwelding.The C.~I~0pi.IA1" SEA-EE-226Page3of6rewiredvalvelimitswitchesshouldbenormallyopenandclosedonlywhenthevalvesare100%closed(i.e.switchclosedwhenthevalvesclosedintheprimarycontainmentisolationposition).ThisactionisbeingtrackedbyNCR87-0021.InordertoprecludetheneedforfutureengineeringanalysisandmaintaincompliancewithRegulatoryGuide1.75,gualifiedElectricalIsolators,capableofwithstanding120VACand250VDC,shouldbeinstalledfornewlyengineereddigitalcomputerinputsdevelopedfromClass1ELimitorquelimitswitches.Thisrecommendationisin-linewithNPE-ElectricalGroupstrategyofeliminatingpotentialpitfallsformaintainingcompliancetotheplantlicensingcommitments.3.0INPUTSANDASSUMPTIONS3.1INPUTSAtSusquehannaSES,computerinputcircuitsarenon-class1EeventhoughtheseinputsaredevelopedfromClass1Emotor-operatedvalves.RegulatoryGuide1.75whichendorsesIEEE384-1974allowstheconnectionoftheselow-energynon-class1EcircuitstoClass1EdevicesprovidedananalysishasbeenperformedtodemonstratethattheClass1Ecircuitsarenotdegradedbelowanacceptablelevelforfaultsonthenon-class1Ecircuits.Computercablesareroutedinnon-classlEracewayswhichalsocontain120VAC,125VDCand250VDCcables.Potentialdamagetocablesinnon-class1Eracewaysmaycauseaccidentalimpositionof120voltsACor250voltsDConcomputerinputwire(s),andthroughthesewirestotheClass1Edevice(s).AsdiscussedinSEA-EE-183,opencontactsofLimitorquelimitswitchescanwithstandimpressedvoltagesof120VACand250VDCacrossthecontacts.However,if120VACor250VDCwereimpressedonclosedcontactsofthelimitswitches,thecontactscouldweldshutifsufficientcurrentflowedforasufficientduration.3.2ThisstudyislimitedtoUnit2digitalcomputerinputsdevelopedfromClass1ELimitorquemotor-operators.ASSUMPTIONSThestudywasbasedonas-builtdrawingsandthedocumentsissuedasofthedateoftaskinitiation.AffiliatedcircuitsinthisstudyweretreatedthesameasClassIEcircuits.Achangeinstateofacomputerinputcontactwhilethereisanimpressedvoltagewasnotconsidered.Onlythecontactintheopenorclosedpositionwasanalyzed.
| | S AnalysisoftheUnit2ClasslEmotor-operated valvesshowsthatthesevalves,exceptforMainSteamLineDrainIsolation ValvesHV-821-2F016 andHV-821-2F019 andtheReactorWaterCleanupIsolation ValvesHV-G33-2F001 andHV-G33-2F004, willmeettheirminimumperformance requirements evenifthecomputerinputlimitswitchesshouldweldshut.Thisconclusion isbaseduponanevaluation thatshows:--Thevalveschangepositionandmeettheirminimumperformance requirements beforethecomputerinputlimitswitchesareexposedtopotential contactwelding,i.e.thevalvelimitswitchesarenormallyopenandtheyclosewhenthevalvechangespositiontoitsisolation position. |
| L\'I~Il~c)~hY K~j~~1SEA-EE-226Page4of64.0METHODSTheSusquehannaSESUnit2I/OSpecificationListing-DigitalRealwasreviewedtoidentifythecomputerinputsdevelopedfromLimitorquemotor-operatorsequippedwithLimitorquelimitswitches.TheSusquehannaSESMotor-OperatorValve(MOV)IndexdatedOctober17,1989andsystemdrawingswerereviewedtodeterminewhichMOVsaresafety-relatedClass1Evalves.Evaluationoftheimpactofwelded-shutLimitorquelimitswitchesusedforcomputerinputswasperformedtoassurethatthesedevicescanperformtheirsafety-relatedfunctionswithweldedcomputerinputlimitswitches.5.0RESULTSReviewoftheSusquehannaSESUnit2I/OSpecificationListingrevealedthatthenumberofcomputerpointsderivedfromClass1ELimitorquelimitswitchesis40.Evaluationofweldedcontactsforeachoftheselimitswitchesisprovided.TheClass1ELimitorquelimitswitchesarepartofmotor-operatedvalveswhichareinoneofthefollowinggroups:l.Affiliated.2.Requirenoautomaticoperation.3.Requireautomaticclosure.Theaffiliatedmotor-operatedvalves,listedinTableI,arepoweredfromClass1Esources.However,thesevalvesandtheirlimitswitchesarenotusedinClass1Ecircuits.Operationofthesevalvesisnotrequiredfordesignbasiseventconditions.Therefore,weldingacomputerinputlimitswitchdoesnoteffectClass1Ecircuits.TheClass1Emotor-operatedvalveswhichrequirenoautomaticoperationarelistedinTable2.Thesevalveshaveopenlimitswitchesforcomputerinputsduringnormalplantlineup.Theselimitswitchesarenotexposedtopotentialwelding.Intheeventthenormalplantlineupischanged,thevalveschangetotheirnewpositionsbeforethecomputerinputlimitswitchesareexposedtopotentialwelding.Therefore,weldingofthecomputerinputlimitswitchesdoesnotpreventthemotor-operatedvalvesfrommeetingtheirminimumperformancerequirements.rInadditiontothevalvesinTable2,theFeedwaterInletStopCheckValvesHV-821-2F032AandHV-821-2F0328motoroperators,whichareintheopenpositionduringnormalplantoperation,arenotrequiredtoautomaticallyoperatefordesignbaseaccidents.However,thesemotoroperatorshaveclosedlimitswitchesforcomputerinputsduringnormalplantoperation.TheFeedwaterInletStopCheckValvesaremotorassistedinordertoprovidethesevalveswithclosingcapability.forprimarycontainmentisolationleakageratetesting.Intheeventthelimitswitchesweldshut,theFeedwaterInletStopCheckValveswillnotbe | | OR-Thevalvesareinaffiliated (associated) circuitsandcontactsfromthesedevicesarenotusedinClass1Ecircuits, i.e.operation ofthevalveisnotrequiredfordesignbasiseventconditions. |
| | IntheeventcomputerinputlimitswitchesforHV-G33-2F001, HV-G33-2F004, HV-821-2F016 andHV-821-2F019 weldshut,thelimitswitchmaindriveshaftscouldperhapsbreaklooseinternaltothevalvescausingthevalvestojam,thuspotentially preventing full.closureofthevalves.Morethanlikelytheweldedshutlimitswitcheswouldcausedamagetothelimitswitchgearing,butwouldnotpreventthesubjectvalvesfromclosing.2.2RECOMMENDATION ToassurethattheHV-G33-2F001, HV-G33-2F004, HV-821-2F016 andHV-821-1F019 valvesmeettheirminimumperformance requirements withimpressed voltagefaultsontheircomputerinputcables,thecomputerinputlimitswitchesshouldberewiredsuchthatthesevalveschangepositionandmeettheirminimumperformance requirements beforethecomputerinputswitchesareexposedtopotential welding.The C.~I~0pi.IA1" SEA-EE-226 Page3of6rewiredvalvelimitswitchesshouldbenormallyopenandclosedonlywhenthevalvesare100%closed(i.e.switchclosedwhenthevalvesclosedintheprimarycontainment isolation position). |
| | ThisactionisbeingtrackedbyNCR87-0021.Inordertoprecludetheneedforfutureengineering analysisandmaintaincompliance withRegulatory Guide1.75,gualified Electrical Isolators, capableofwithstanding 120VACand250VDC,shouldbeinstalled fornewlyengineered digitalcomputerinputsdeveloped fromClass1ELimitorque limitswitches. |
| | Thisrecommendation isin-linewithNPE-Electrical Groupstrategyofeliminating potential pitfallsformaintaining compliance totheplantlicensing commitments. |
| | |
| | ==3.0 INPUTSANDASSUMPTIONS== |
| | 3.1INPUTSAtSusquehanna SES,computerinputcircuitsarenon-class 1Eeventhoughtheseinputsaredeveloped fromClass1Emotor-operated valves.Regulatory Guide1.75whichendorsesIEEE384-1974allowstheconnection oftheselow-energy non-class 1EcircuitstoClass1Edevicesprovidedananalysishasbeenperformed todemonstrate thattheClass1Ecircuitsarenotdegradedbelowanacceptable levelforfaultsonthenon-class 1Ecircuits. |
| | Computercablesareroutedinnon-class lEracewayswhichalsocontain120VAC,125VDCand250VDCcables.Potential damagetocablesinnon-class 1Eracewaysmaycauseaccidental imposition of120voltsACor250voltsDConcomputerinputwire(s),andthroughthesewirestotheClass1Edevice(s). |
| | Asdiscussed inSEA-EE-183, opencontactsofLimitorque limitswitchescanwithstand impressed voltagesof120VACand250VDCacrossthecontacts. |
| | However,if120VACor250VDCwereimpressed onclosedcontactsofthelimitswitches, thecontactscouldweldshutifsufficient currentflowedforasufficient duration. |
| | 3.2ThisstudyislimitedtoUnit2digitalcomputerinputsdeveloped fromClass1ELimitorque motor-operators. |
| | ASSUMPTIONS Thestudywasbasedonas-builtdrawingsandthedocuments issuedasofthedateoftaskinitiation. |
| | Affiliated circuitsinthisstudyweretreatedthesameasClassIEcircuits. |
| | Achangeinstateofacomputerinputcontactwhilethereisanimpressed voltagewasnotconsidered. |
| | Onlythecontactintheopenorclosedpositionwasanalyzed. |
| | L\'I~Il~c)~hY K~j~~1SEA-EE-226 Page4of64.0METHODSTheSusquehanna SESUnit2I/OSpecification Listing-DigitalRealwasreviewedtoidentifythecomputerinputsdeveloped fromLimitorque motor-operators equippedwithLimitorque limitswitches. |
| | TheSusquehanna SESMotor-Operator Valve(MOV)IndexdatedOctober17,1989andsystemdrawingswerereviewedtodetermine whichMOVsaresafety-related Class1Evalves.Evaluation oftheimpactofwelded-shut Limitorque limitswitchesusedforcomputerinputswasperformed toassurethatthesedevicescanperformtheirsafety-related functions withweldedcomputerinputlimitswitches. |
| | |
| | ==5.0 RESULTSReviewoftheSusquehanna== |
| | SESUnit2I/OSpecification ListingrevealedthatthenumberofcomputerpointsderivedfromClass1ELimitorque limitswitchesis40.Evaluation ofweldedcontactsforeachoftheselimitswitchesisprovided. |
| | TheClass1ELimitorque limitswitchesarepartofmotor-operated valveswhichareinoneofthefollowing groups:l.Affiliated. |
| | 2.Requirenoautomatic operation. |
| | 3.Requireautomatic closure.Theaffiliated motor-operated valves,listedinTableI,arepoweredfromClass1Esources.However,thesevalvesandtheirlimitswitchesarenotusedinClass1Ecircuits. |
| | Operation ofthesevalvesisnotrequiredfordesignbasiseventconditions. |
| | Therefore, weldingacomputerinputlimitswitchdoesnoteffectClass1Ecircuits. |
| | TheClass1Emotor-operated valveswhichrequirenoautomatic operation arelistedinTable2.Thesevalveshaveopenlimitswitchesforcomputerinputsduringnormalplantlineup.Theselimitswitchesarenotexposedtopotential welding.Intheeventthenormalplantlineupischanged,thevalveschangetotheirnewpositions beforethecomputerinputlimitswitchesareexposedtopotential welding.Therefore, weldingofthecomputerinputlimitswitchesdoesnotpreventthemotor-operated valvesfrommeetingtheirminimumperformance requirements. |
| | rInadditiontothevalvesinTable2,theFeedwater InletStopCheckValvesHV-821-2F032A andHV-821-2F0328 motoroperators, whichareintheopenpositionduringnormalplantoperation, arenotrequiredtoautomatically operatefordesignbaseaccidents. |
| | However,thesemotoroperators haveclosedlimitswitchesforcomputerinputsduringnormalplantoperation. |
| | TheFeedwater InletStopCheckValvesaremotorassistedinordertoprovidethesevalveswithclosingcapability. |
| | forprimarycontainment isolation leakageratetesting.Intheeventthelimitswitchesweldshut,theFeedwater InletStopCheckValveswillnotbe |
| ~~WEqrt4lipa~ | | ~~WEqrt4lipa~ |
| SEA-EE-226Page5of6preventedfromclosingfordesignbaseaccidentssincethesevalvesarecheckvalves.Therefore,theweldingofthecomputerinputlimitswitchesdoesnotpreventHV-B21-2F032AandHV-B21-2F032Bfrommeetingtheirminimumperformancerequirements.TheClass1Evalveswhicharerequiredtooperatefordesignbaseaccidentsareevaluatedbelow:TheESWDiesel"E"CoolerSupplyValvesNos.HV-01110EandHV-01120EarerequiredtoautomaticallycloseforcertainDBA'swhentheDieselGenerator"E"isnotalignedandisbeingtested.Forthiscondition,thecomputerinputlimitswitchesareopenandarenotexposedtopotentialwelding.Ifthesevalvesreceiveanautomaticclosesignal,thevalvechangespositionbeforethecomputerinputlimitswitchesareexposedtopotentialwelding.Therefore,theweldingofthesecomputerinputlimitswitchesdoesnotpreventHV-01110EandHV-01120Efrommeetingtheirminimumperformancerequirements.TheReactorWaterCleanupIsolationValvesHV-G33-2F001andHV-G33-2F004andtheMainSteamLineDrainIsolationValvesHV-B21-2F016andHV-B21-2F019arerequiredtoautomaticallycloseforcertainDBA's.However,thecomputerinputlimitswitchesfromthesevalvesareclosedwhenthesevaivesareopen.Intheeventthecomputerinputlimitswitchesweldshut,thelimitswitchmaindriveshaftscouldperhapsbreaklooseinternaltothevalvescausingthevalvestojam,thuspotentiallypreventingfullclosureofthevalves.PerDanWarsingofLimitorqueCorp.,thisisveryunlikely.Morethanlikely,theweldedshutlimitswitchwillcausedamagetothelimitswitchgearing,butwillnotpreventthevalvesfromclosing.ToassurethattheHV-G33-2F001,HV-G33-2F004,HV-B21-2F016andHV-B21-2F019valvesmeettheirminimumperformancerequirementswithimpressedvoltagefaultsontheircomputerinputcables,thecomputerinputlimitswitchesshouldberewiredsuchthatthesevalveschangepositionsandmeettheirminimumperformancerequirementsbeforethecomputerinputswitchesareexposedtopotentialwelding.Therewiredvalvelimitswitchesshouldbenormallyopenandclosedonlywhen'thevalvesare100%closed(i.e.switchclosedwhenthevalvesclosedintheprimarycontainmentisolationposition).ThisactionisbeingtrackedbyNCR87-0021.REFERENCES6.1IEEE279-1971.6.2IEEE384-1974.6.3RegulatoryGuide1.75,Rev.0.6.4SusquehannaSESUnit2I/OSpecificationListingdated'ec.8,1989.6.5SusquehannaSESMotor-OperatorValveIndexdatedOct.17,1989.6.6SEA-EE-183,Rev.0.6.7SusquehannaSESDesignDescriptionManualChapter5,15and31.jpa/rpa042i(18) | | SEA-EE-226 Page5of6prevented fromclosingfordesignbaseaccidents sincethesevalvesarecheckvalves.Therefore, theweldingofthecomputerinputlimitswitchesdoesnotpreventHV-B21-2F032A andHV-B21-2F032B frommeetingtheirminimumperformance requirements. |
| ~~Iv SEA-EE-226Page6of6TABLE1AFFILIATEDMOTOR-OPERATEDVALVESHY-821-2F001HV-821-2F002HV-821-2F005HV-831-2F023AHV-831-2F0238HV-831-2F031AHV-831-2F0318HV-831-2F032AHV-831-2F0328TABLE2MOTOR-OPERATEDVALVESNOAUTOMATICOPERATIONHV-01112AHV-011128HV-01112CHV-01112DHV-01110AHV-011108HV-01110CHV-011100HV-01122AHV-011228HV-01122CHV-01122DHV-01120AHV-011208HV-01120CHV-011200HV-01112EHV-01122EHV-821-2F020HV-G33-2F042HV-G33-2F104HV-24182AHV-241828jpa/rpa042i(18) r~~~~~<<f>>4}} | | TheClass1Evalveswhicharerequiredtooperatefordesignbaseaccidents areevaluated below:TheESWDiesel"E"CoolerSupplyValvesNos.HV-01110E andHV-01120E arerequiredtoautomatically closeforcertainDBA'swhentheDieselGenerator "E"isnotalignedandisbeingtested.Forthiscondition, thecomputerinputlimitswitchesareopenandarenotexposedtopotential welding.Ifthesevalvesreceiveanautomatic closesignal,thevalvechangespositionbeforethecomputerinputlimitswitchesareexposedtopotential welding.Therefore, theweldingofthesecomputerinputlimitswitchesdoesnotpreventHV-01110E andHV-01120E frommeetingtheirminimumperformance requirements. |
| | TheReactorWaterCleanupIsolation ValvesHV-G33-2F001 andHV-G33-2F004 andtheMainSteamLineDrainIsolation ValvesHV-B21-2F016 andHV-B21-2F019 arerequiredtoautomatically closeforcertainDBA's.However,thecomputerinputlimitswitchesfromthesevalvesareclosedwhenthesevaivesareopen.Intheeventthecomputerinputlimitswitchesweldshut,thelimitswitchmaindriveshaftscouldperhapsbreaklooseinternaltothevalvescausingthevalvestojam,thuspotentially preventing fullclosureofthevalves.PerDanWarsingofLimitorque Corp.,thisisveryunlikely. |
| | Morethanlikely,theweldedshutlimitswitchwillcausedamagetothelimitswitchgearing,butwillnotpreventthevalvesfromclosing.ToassurethattheHV-G33-2F001, HV-G33-2F004, HV-B21-2F016 andHV-B21-2F019 valvesmeettheirminimumperformance requirements withimpressed voltagefaultsontheircomputerinputcables,thecomputerinputlimitswitchesshouldberewiredsuchthatthesevalveschangepositions andmeettheirminimumperformance requirements beforethecomputerinputswitchesareexposedtopotential welding.Therewiredvalvelimitswitchesshouldbenormallyopenandclosedonlywhen'thevalvesare100%closed(i.e.switchclosedwhenthevalvesclosedintheprimarycontainment isolation position). |
| | ThisactionisbeingtrackedbyNCR87-0021.REFERENCES 6.1IEEE279-1971. |
| | 6.2IEEE384-1974. |
| | 6.3Regulatory Guide1.75,Rev.0.6.4Susquehanna SESUnit2I/OSpecification Listingdated'ec. |
| | 8,1989.6.5Susquehanna SESMotor-Operator ValveIndexdatedOct.17,1989.6.6SEA-EE-183, Rev.0.6.7Susquehanna SESDesignDescription ManualChapter5,15and31.jpa/rpa042i(18) |
| | ~~Iv SEA-EE-226 Page6of6TABLE1AFFILIATED MOTOR-OPERATED VALVESHY-821-2F001 HV-821-2F002 HV-821-2F005 HV-831-2F023A HV-831-2F0238 HV-831-2F031A HV-831-2F0318 HV-831-2F032A HV-831-2F0328 TABLE2MOTOR-OPERATED VALVESNOAUTOMATIC OPERATION HV-01112A HV-011128 HV-01112C HV-01112D HV-01110A HV-011108 HV-01110C HV-011100 HV-01122A HV-011228 HV-01122C HV-01122DHV-01120A HV-011208 HV-01120C HV-011200 HV-01112E HV-01122EHV-821-2F020 HV-G33-2F042 HV-G33-2F104 HV-24182A HV-241828 jpa/rpa042i (18) r~~~~~<<f>>4}} |
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Category:GENERAL EXTERNAL TECHNICAL REPORTS
MONTHYEARML20217A9931999-09-30030 September 1999
NRC Regulatory Assessment & Oversight Pilot Program, Performance Indicator Data
ML17146B1741999-08-0303 August 1999
GL 96-06 Risk Assessment for Sses.
ML20195B2381999-03-31031 March 1999
Redacted Version for 10CFR2.790 Request for Decommissioning Status Rept for Sses,Units 1 & 2
ML20217Q4891998-04-21021 April 1998
Rev 1 to Draft LDCN 2482, FSAR Chapter 13.4 & FSAR Chapter 17.2 Changes to Support ITS Implementation
ML20155F7661996-07-25025 July 1996
Partially Deleted Job Number 739619-96, Investigation of E Diesel Breaker Misalignment
ML20155F7491996-07-24024 July 1996
Independent Safety Evaluation Svcs Project Rept 3-96, Investigation of E Diesel Generator In-Operability Event
ML17164A6631995-04-11011 April 1995
Impact of Extending T-10 AOT from 3 to 7 Days.
ML18026A5351994-10-31031 October 1994
SSES Unit 1 & 2 MSIV Leakage Alternate Treatment Method Seismic Evaluation. W/One Oversize Drawing
ML17158A1631993-12-0909 December 1993
Remote Indication of Spent Fuel Pool Level & Temperature.
ML18026A4281993-08-16016 August 1993
PP&L Response to NRC Concerns Re Loss of Spent Fuel Pool Cooling Following Loca,Sses,Units 1 & 2.
ML17157C1421992-10-21021 October 1992
Engineering Assessment of Fuel Pool Cooling Piping EDR-G20020.
ML17157C1401992-08-31031 August 1992
Review of Fuel Pool Cooling During Postulated Off-Normal & Accident Events SSES Units 1 & 2.
ML17157C1411992-08-31031 August 1992
Loss of Fuel Pool Cooling Event Evaluation.
ML20082C4941992-08-14014 August 1992
Evaluation of Unit 1 & Unit 2 Derating of Power Cables in Raceways Wrapped W/Thermo-Lag Matl
ML17157C1381992-07-27027 July 1992
Safety Consequences of Boiling Spent Fuel Pool at Susquehanna Steam Electric Station.
ML17157B0971990-11-0505 November 1990
COTTAP-2,Rev 1 Theory & Input Description Manual.
ML20065L6651990-10-31031 October 1990
Environ Qualification Analysis of 250 Volt DC Limitorque Motor Operators for Valves Located Outside Containment of Susquehanna Steam Electric Station
ML17157A4211990-08-31031 August 1990
Analysis of Pitting Corrosion Failures in ESW Sys RHR Lube Oil Coolers & RCIC Pump Room Unit Coolers at Susquehanna Steam Electric Station.
ML17157A2171990-05-0303 May 1990
Rev 1 to SEA-EE-183, Evaluation of Unit 1 Computer Class 1E - Non-Class 1E Interfaces.
ML17157A2191990-05-0303 May 1990
Rev 1 to SEA-EE-184, Evaluation of Unit 1 Annunciator Class 1E - Non-Class 1E Interfaces.
ML17157A2201990-05-0303 May 1990
Rev 1 to SEA-EE-226, Evaluation of Welded Shut Class 1E Limitorque Limit Switches Used for Unit 2 Computer Inputs.
ML17157A2221990-04-17017 April 1990
Rev 0 to SEA-EE-235, Evaluation of Potential High Voltage Sources Into Unit 1 & 2 Computers.
ML17157A2211990-04-12012 April 1990
Rev 0 to SEA-EE-231, Evaluation of Welded Contacts of Class 1E Circuit Breaker Auxiliary Switches & Limit Switches Used for Unit 2 & Common Annunciator Inputs.
ML20005F9831990-01-0505 January 1990
Rev 0 to Analysis of B & C 1989 Diesels Failure.
ML20235Z1801989-01-31031 January 1989
Rev 2 to Pennsylvania Power & Light Co Approach to Risk Mgt & Risk Assessment
ML17156A6921988-07-31031 July 1988
CRD Housing Cap Screw Corrosion.
ML17146B0951987-11-30030 November 1987
Rev 1 to Susquehanna Unit 2 Cycle 3 Reload Analysis Design & Safety Analyses.
ML17146B0941987-11-30030 November 1987
Rev 1 to Susquehanna Unit 2 Cycle 3 Plant Transient Analysis.
ML18040A8521987-08-31031 August 1987
Suppl 4 to Evaluation of Selected Fire Door & Door Frame Assemblies, Technical Rept
ML17146B0101987-05-31031 May 1987
Suppl 3 to Evaluation of Selected Fire Door Frame Assemblies, Technical Rept
ML17146B0091986-06-30030 June 1986
Suppl 2 to Evaluation of Selected Fire Door & Door Frame Assemblies, Technical Rept
ML18040B1191985-08-31031 August 1985
Suppl 1 to Evaluation of Selected Fire Door & Door Frame Assemblies.
ML18040B1291985-04-17017 April 1985
Fact-Finding Rept on Air Duct Penetrations Through 1 H Fire Resistive Wall Assembly.
ML20102C2131985-03-0101 March 1985
Detailed Control Room Design Review Supplementary Summary Rept
ML18040A7861985-01-31031 January 1985
Evaluation of Selected Fire Door & Door Frame Assemblies, Technical Rept
ML20092J2391984-06-0606 June 1984
Investigation of Unit 2 Power Transient of 840528. Related Info Encl
ML20091B3401984-02-10010 February 1984
Reactor Mode Switch Functional Testing & Wear Characteristics Evaluation, Final Rept
ML18040B0231983-09-0909 September 1983
Rev 4 to Equipment Qualification Rept.
ML20023D1651983-04-29029 April 1983
Reactor Mode Switch Failure Modes & Mechanisms, Final Rept
ML18031A4071982-10-27027 October 1982
Addendum to Final Rept Independent Design Review- Susquehanna Steam Electric Station.
ML17139B0421982-08-24024 August 1982
Suppl to Investigation of Unit 1 Small Piping Sys Design Installation & Insp Program Adequacy & Implementation. Viewgraphs Encl
ML17139B0401982-08-23023 August 1982
Investigation of Unit 1 Small Piping Sys Design Installation & Insp Program Adequacy & Implementation.
ML18031A3861982-07-23023 July 1982
Pool Swell Forcing Functions for Mark II Wetwell-to-Drywell Vacuum Breakers.
ML20050C2991982-04-30030 April 1982
Design Assessment Rept, Vol 2,Revision 6
ML17139B8881982-03-31031 March 1982
App D to Rev 1 to Control Sys Power Supply & Sensor Malfunction Study, Commonality Diagrams.
ML17139B8851982-03-31031 March 1982
Rev 1 to Control Sys Power Supply & Sensor Malfunction Study.
ML17139B8901982-03-31031 March 1982
App E to Rev 1 to Control Sys Power Supply & Sensor Malfunction Study, Failure Modes & Effects Analysis.
ML17139B8911982-03-31031 March 1982
App F to Rev 1 to Control Sys Power Supply & Sensor Malfunction Study, Malfunction Analysis Tables.
ML18040B0271982-03-31031 March 1982
App C to Rev 1 to Control Sys Power Supply & Sensor Malfunction Study, Control Sys Identification Diagrams. W/Five Oversize Diagrams.Aperture Cards Are Available in PDR
ML18040A7091982-03-31031 March 1982
App B to Rev 1 to Control Sys Power Supply & Sensor Malfunction Study, Control Sys & Safety Functions.
1999-09-30
[Table view]
Category:TEXT-SAFETY REPORT
MONTHYEARML20217A9931999-09-30030 September 1999
NRC Regulatory Assessment & Oversight Pilot Program, Performance Indicator Data
ML17146B1741999-08-0303 August 1999
GL 96-06 Risk Assessment for Sses.
ML20206D3331999-04-27027 April 1999
SER of Individual Plant Examination of External Events Submittal on Susquehanna Steam Electric Station,Units 1 & 2. Staff Notes That Licensee IPEEE Complete with Regard to Info Requested by Suppl 4 to GL 88-20
ML20195B2381999-03-31031 March 1999
Redacted Version for 10CFR2.790 Request for Decommissioning Status Rept for Sses,Units 1 & 2
ML17164A8451998-10-31031 October 1998
SSES Unit 1 Tenth Refueling & Insp Outage ISI Outage Summary Rept.
ML20236N6751998-07-0909 July 1998
Part 21 & Deficiency Rept Re Notification of Potential Safety Hazard from Breakage of Cast Iron Suction Heads in Apkd Type Pumps.Caused by Migration of Suction Head Journal Sleeve Along Lower End of Pump Shaft.Will Inspect Pumps
ML20217Q4891998-04-21021 April 1998
Rev 1 to Draft LDCN 2482, FSAR Chapter 13.4 & FSAR Chapter 17.2 Changes to Support ITS Implementation
ML18026A4931998-03-30030 March 1998
LER 97-007-01:on 971017,entry Into TS 3.0.3 Occurred to Allow Completion of Surveillance Testing of One Channel of Rbm.Caused by Failure of Components in LPRM Output to Rbm. Submitted TS Change Request to Extend LCO Action Statement
ML18026A5401998-02-28028 February 1998
Monthly Operating Repts for Feb 1998 for Susquehanna Steam Electric Station.W/980313 Ltr
ML18026A4891997-11-17017 November 1997
LER 97-007-00:on 971017,TS 3.0.3 Entry Voluntarily Made. Caused by Inadequate Post Maint Testing Following Earlier Work Associated W/Components.Failed Components Repaired, Replaced & Testing Completed
ML18017A2921997-10-28028 October 1997
1997 Nrc/Fema Observed Exercise.
ML17158C1861997-06-0505 June 1997
Proceedings of Intl Topical Meeting on Advanced Reactors Safety Vol II, on 970601-05
ML20140A9661997-05-29029 May 1997
Part 21 Rept Re Ksv Emergency Diesel Generator Power Piston Failure.Caused by Jacket Water in Combustion Chamber. Recommends That Users Verify That Crown Thickness at Valve Cutout Be 100 Minimum
ML18026A4781997-03-28028 March 1997
Rev 1 to Application of Anfb to ATRIUM-10 for Susquehanna Reloads.
ML20137G6261997-03-25025 March 1997
Svcs Part 21 Rept Re Emergency Generators Installed at Zion Station Which Developed Significant Drop in Crankcase Lube Oil Level.Caused by Crack in Liner Wall,Allowing Jacket Water to Enter Chamber
ML20155F7661996-07-25025 July 1996
Partially Deleted Job Number 739619-96, Investigation of E Diesel Breaker Misalignment
ML20155F7491996-07-24024 July 1996
Independent Safety Evaluation Svcs Project Rept 3-96, Investigation of E Diesel Generator In-Operability Event
ML20117G4641996-05-14014 May 1996
Part 21 Rept Re Cooper Bessemer Reciprocating Products,Div of Cooper Cameron Corp,Issued Ltr to Define Utils/Plants Containing Similar Equipment as Supplied on Cooper Bessemer Ksv & Enterprise Dsr EDGs
ML18026A5961996-01-0202 January 1996
LER 95-013-00:on 951119,thermally Induced Pressure Locking of HPCI Valve Occurred Under Bonnet Pressure of 3,000-7,000 Psig.Damaged HPCI Injection Valve repaired.W/960102 Ltr
ML18017A0511995-11-30030 November 1995
Monthly Operating Repts for Nov 1995 for SSES Units 1 & 2. W/951215 Ltr
ML20092H7641995-08-31031 August 1995
Monthly Operating Repts for Aug 1995 for Susquehanna Ses
ML17158A8771995-08-15015 August 1995
Exercise Manual.
ML17158A8061995-07-14014 July 1995
Books 1 & 2 of ISI Outage Summary Rept SSES Unit 1 8th Refuel Outage.
ML18017A0461995-07-0707 July 1995
LER 95-008-00:on 950609,shift Average Licensed Core Thermal Power Was Exceeded.Caused by Failed Instrumentation Drift. Repaired & Recalibrated Subject Instrumentation
ML17164A6631995-04-11011 April 1995
Impact of Extending T-10 AOT from 3 to 7 Days.
ML17164A5871995-01-31031 January 1995
Monthly Operating Repts for Jan 1995 for Susquehanna Ses
ML18026A5351994-10-31031 October 1994
SSES Unit 1 & 2 MSIV Leakage Alternate Treatment Method Seismic Evaluation. W/One Oversize Drawing
ML17158A4821994-08-23023 August 1994
ISI Outage Summary Rept Unit 2 6th Refueling Outage, Books 1 & 2 of 2
ML17158A2391994-04-0505 April 1994
Books 1 & 2 of SSES Unit 1 Seventh Refueling & Insp Outage ISI Outage Summary Rept.
ML18017A2701993-12-31031 December 1993
PP&L Annual Rept 1993.
ML17158A2651993-12-31031 December 1993
Allegheny Electric Cooperative,Inc Annual Rept 1993.
ML17158A1631993-12-0909 December 1993
Remote Indication of Spent Fuel Pool Level & Temperature.
ML18026A4281993-08-16016 August 1993
PP&L Response to NRC Concerns Re Loss of Spent Fuel Pool Cooling Following Loca,Sses,Units 1 & 2.
ML18026A4261993-06-0909 June 1993
LER 90-007-01:on 900705,primary Power Supply to RPS a Power Distribution Panel Lost When One Electrical Protection Assembly (EPA) Breaker Tripped.Epa Logic Cards Reviewed & RPS Power Supply Will Be redesigned.W/930609 Ltr
ML17157C2441993-02-28028 February 1993
Monthly Operating Rept for Feb 1993 for Susquehanna Steam Electric Station,Units 1 & 2
ML18017A2031993-02-0101 February 1993
Books 1 & 2 of Unit 2 Fifth Refueling & Insp Outage,Isi Outage Summary Rept.
ML20044C2741993-01-31031 January 1993
Corrected Monthly Operating Rept for Jan 1993 for Susquehanna Steam Electric Station,Unit 2,consisting of Info on Unit Shutdowns & Power Reductions
ML17157C3691992-12-31031 December 1992
PP&L Annual Rept 1992.
ML20056C3941992-12-31031 December 1992
Allegheny Electric Cooperative,Inc Annual Rept 1992
ML18017A0421992-12-14014 December 1992
Suppl to 921127 Part 21 Rept Re High Air Concentration in Reactor Bldg Making Area Uninhabitable for Retrieving Air Filters,Per NUREG-0737,Item II.F.1.Util Current Position Re Fuel Pool Cooling Issues Contrary to Reg Guide 1.3
ML18026A2481992-11-27027 November 1992
Part 21 Rept Re Substantial Safety Hazard in Design of Facility for Loss of Normal Spent Fuel Pool Cooling
ML18026A4231992-11-17017 November 1992
LER 92-016-00:on 920416,discovered That Existing Analysis for Two Spent Fuel Storage Pools Did Not Reflect Current Fuel Design & Plant Operation.Caused by Failure to Modify FSAR Analysis.Fsar Will Be revised.W/921117 Ltr
ML17157C1421992-10-21021 October 1992
Engineering Assessment of Fuel Pool Cooling Piping EDR-G20020.
ML17157C1411992-08-31031 August 1992
Loss of Fuel Pool Cooling Event Evaluation.
ML17157C1401992-08-31031 August 1992
Review of Fuel Pool Cooling During Postulated Off-Normal & Accident Events SSES Units 1 & 2.
ML20082C4941992-08-14014 August 1992
Evaluation of Unit 1 & Unit 2 Derating of Power Cables in Raceways Wrapped W/Thermo-Lag Matl
ML17157C1381992-07-27027 July 1992
Safety Consequences of Boiling Spent Fuel Pool at Susquehanna Steam Electric Station.
ML17157B9331992-07-24024 July 1992
Sixth Refueling & Insp Outage Inservice Insp Outage Summary Rept, Books 1 & 2
ML20097D4681991-12-31031 December 1991
Pennsylvania Power & Light Company,1991 Annual Rept
ML18017A0391991-07-26026 July 1991
LER 91-010-00:on 910628,RWCU Isolated on Two Occassions Due to Actuations of Steam Leak Detection Instrumentation. Caused by Design Deficiency & Elevated Ambient Penetration Room Temps.Temp Modules replaced.W/910726 Ltr
1999-09-30
[Table view] |
Text
QwjwII~~ENGINEERING STUDIES,ANALYSES, ANDEVALUATIONS COVERSHEET OIAI.ITYI.EYEI.AFETYASIDERTIIEDIIOIINAI.ITYED/CTIIND,.SEAIIODcrIID.FADEIOF4yEVALUATION OFWELDEDSHUTCLASS1ELIMITORQUE LIMITSWITCHESUSEDFORUNIT2COMPUTERINP9006290165 900619PDRADOCK05000337PPDCOI3ogo,peak~Ill+/y~REVISIONNO.DATEPREPAREDBYI'IoREVIEIEDBYPPROVEDB IEI~'ILA")
SEA-EE-226 Page2of6EVALUATION OFWELDEDSHUTCLASS1ELIMITORQUE LIHITSWITCHESUSEDFORUNIT2COMPUTERINPUTS1.0SCOPEThepurposeofthisSEAistoevaluatetheimpactofaweldedshutlimitswitchfromClasslELimitorque motoroperators ontheoperation oftheClass1Evalve.SEA-EE-183 determined thatclosedLimitorque computerinputlimitswitchescouldweldshutforimpressed voltagefaults.
2.0CONCLUSION
S ANDRECOMMENDATIONS
2.1CONCLUSION
S AnalysisoftheUnit2ClasslEmotor-operated valvesshowsthatthesevalves,exceptforMainSteamLineDrainIsolation ValvesHV-821-2F016 andHV-821-2F019 andtheReactorWaterCleanupIsolation ValvesHV-G33-2F001 andHV-G33-2F004, willmeettheirminimumperformance requirements evenifthecomputerinputlimitswitchesshouldweldshut.Thisconclusion isbaseduponanevaluation thatshows:--Thevalveschangepositionandmeettheirminimumperformance requirements beforethecomputerinputlimitswitchesareexposedtopotential contactwelding,i.e.thevalvelimitswitchesarenormallyopenandtheyclosewhenthevalvechangespositiontoitsisolation position.
OR-Thevalvesareinaffiliated (associated) circuitsandcontactsfromthesedevicesarenotusedinClass1Ecircuits, i.e.operation ofthevalveisnotrequiredfordesignbasiseventconditions.
IntheeventcomputerinputlimitswitchesforHV-G33-2F001, HV-G33-2F004, HV-821-2F016 andHV-821-2F019 weldshut,thelimitswitchmaindriveshaftscouldperhapsbreaklooseinternaltothevalvescausingthevalvestojam,thuspotentially preventing full.closureofthevalves.Morethanlikelytheweldedshutlimitswitcheswouldcausedamagetothelimitswitchgearing,butwouldnotpreventthesubjectvalvesfromclosing.2.2RECOMMENDATION ToassurethattheHV-G33-2F001, HV-G33-2F004, HV-821-2F016 andHV-821-1F019 valvesmeettheirminimumperformance requirements withimpressed voltagefaultsontheircomputerinputcables,thecomputerinputlimitswitchesshouldberewiredsuchthatthesevalveschangepositionandmeettheirminimumperformance requirements beforethecomputerinputswitchesareexposedtopotential welding.The C.~I~0pi.IA1" SEA-EE-226 Page3of6rewiredvalvelimitswitchesshouldbenormallyopenandclosedonlywhenthevalvesare100%closed(i.e.switchclosedwhenthevalvesclosedintheprimarycontainment isolation position).
ThisactionisbeingtrackedbyNCR87-0021.Inordertoprecludetheneedforfutureengineering analysisandmaintaincompliance withRegulatory Guide1.75,gualified Electrical Isolators, capableofwithstanding 120VACand250VDC,shouldbeinstalled fornewlyengineered digitalcomputerinputsdeveloped fromClass1ELimitorque limitswitches.
Thisrecommendation isin-linewithNPE-Electrical Groupstrategyofeliminating potential pitfallsformaintaining compliance totheplantlicensing commitments.
3.0 INPUTSANDASSUMPTIONS
3.1INPUTSAtSusquehanna SES,computerinputcircuitsarenon-class 1Eeventhoughtheseinputsaredeveloped fromClass1Emotor-operated valves.Regulatory Guide1.75whichendorsesIEEE384-1974allowstheconnection oftheselow-energy non-class 1EcircuitstoClass1Edevicesprovidedananalysishasbeenperformed todemonstrate thattheClass1Ecircuitsarenotdegradedbelowanacceptable levelforfaultsonthenon-class 1Ecircuits.
Computercablesareroutedinnon-class lEracewayswhichalsocontain120VAC,125VDCand250VDCcables.Potential damagetocablesinnon-class 1Eracewaysmaycauseaccidental imposition of120voltsACor250voltsDConcomputerinputwire(s),andthroughthesewirestotheClass1Edevice(s).
Asdiscussed inSEA-EE-183, opencontactsofLimitorque limitswitchescanwithstand impressed voltagesof120VACand250VDCacrossthecontacts.
However,if120VACor250VDCwereimpressed onclosedcontactsofthelimitswitches, thecontactscouldweldshutifsufficient currentflowedforasufficient duration.
3.2ThisstudyislimitedtoUnit2digitalcomputerinputsdeveloped fromClass1ELimitorque motor-operators.
ASSUMPTIONS Thestudywasbasedonas-builtdrawingsandthedocuments issuedasofthedateoftaskinitiation.
Affiliated circuitsinthisstudyweretreatedthesameasClassIEcircuits.
Achangeinstateofacomputerinputcontactwhilethereisanimpressed voltagewasnotconsidered.
Onlythecontactintheopenorclosedpositionwasanalyzed.
L\'I~Il~c)~hY K~j~~1SEA-EE-226 Page4of64.0METHODSTheSusquehanna SESUnit2I/OSpecification Listing-DigitalRealwasreviewedtoidentifythecomputerinputsdeveloped fromLimitorque motor-operators equippedwithLimitorque limitswitches.
TheSusquehanna SESMotor-Operator Valve(MOV)IndexdatedOctober17,1989andsystemdrawingswerereviewedtodetermine whichMOVsaresafety-related Class1Evalves.Evaluation oftheimpactofwelded-shut Limitorque limitswitchesusedforcomputerinputswasperformed toassurethatthesedevicescanperformtheirsafety-related functions withweldedcomputerinputlimitswitches.
5.0 RESULTSReviewoftheSusquehanna
SESUnit2I/OSpecification ListingrevealedthatthenumberofcomputerpointsderivedfromClass1ELimitorque limitswitchesis40.Evaluation ofweldedcontactsforeachoftheselimitswitchesisprovided.
TheClass1ELimitorque limitswitchesarepartofmotor-operated valveswhichareinoneofthefollowing groups:l.Affiliated.
2.Requirenoautomatic operation.
3.Requireautomatic closure.Theaffiliated motor-operated valves,listedinTableI,arepoweredfromClass1Esources.However,thesevalvesandtheirlimitswitchesarenotusedinClass1Ecircuits.
Operation ofthesevalvesisnotrequiredfordesignbasiseventconditions.
Therefore, weldingacomputerinputlimitswitchdoesnoteffectClass1Ecircuits.
TheClass1Emotor-operated valveswhichrequirenoautomatic operation arelistedinTable2.Thesevalveshaveopenlimitswitchesforcomputerinputsduringnormalplantlineup.Theselimitswitchesarenotexposedtopotential welding.Intheeventthenormalplantlineupischanged,thevalveschangetotheirnewpositions beforethecomputerinputlimitswitchesareexposedtopotential welding.Therefore, weldingofthecomputerinputlimitswitchesdoesnotpreventthemotor-operated valvesfrommeetingtheirminimumperformance requirements.
rInadditiontothevalvesinTable2,theFeedwater InletStopCheckValvesHV-821-2F032A andHV-821-2F0328 motoroperators, whichareintheopenpositionduringnormalplantoperation, arenotrequiredtoautomatically operatefordesignbaseaccidents.
However,thesemotoroperators haveclosedlimitswitchesforcomputerinputsduringnormalplantoperation.
TheFeedwater InletStopCheckValvesaremotorassistedinordertoprovidethesevalveswithclosingcapability.
forprimarycontainment isolation leakageratetesting.Intheeventthelimitswitchesweldshut,theFeedwater InletStopCheckValveswillnotbe
~~WEqrt4lipa~
SEA-EE-226 Page5of6prevented fromclosingfordesignbaseaccidents sincethesevalvesarecheckvalves.Therefore, theweldingofthecomputerinputlimitswitchesdoesnotpreventHV-B21-2F032A andHV-B21-2F032B frommeetingtheirminimumperformance requirements.
TheClass1Evalveswhicharerequiredtooperatefordesignbaseaccidents areevaluated below:TheESWDiesel"E"CoolerSupplyValvesNos.HV-01110E andHV-01120E arerequiredtoautomatically closeforcertainDBA'swhentheDieselGenerator "E"isnotalignedandisbeingtested.Forthiscondition, thecomputerinputlimitswitchesareopenandarenotexposedtopotential welding.Ifthesevalvesreceiveanautomatic closesignal,thevalvechangespositionbeforethecomputerinputlimitswitchesareexposedtopotential welding.Therefore, theweldingofthesecomputerinputlimitswitchesdoesnotpreventHV-01110E andHV-01120E frommeetingtheirminimumperformance requirements.
TheReactorWaterCleanupIsolation ValvesHV-G33-2F001 andHV-G33-2F004 andtheMainSteamLineDrainIsolation ValvesHV-B21-2F016 andHV-B21-2F019 arerequiredtoautomatically closeforcertainDBA's.However,thecomputerinputlimitswitchesfromthesevalvesareclosedwhenthesevaivesareopen.Intheeventthecomputerinputlimitswitchesweldshut,thelimitswitchmaindriveshaftscouldperhapsbreaklooseinternaltothevalvescausingthevalvestojam,thuspotentially preventing fullclosureofthevalves.PerDanWarsingofLimitorque Corp.,thisisveryunlikely.
Morethanlikely,theweldedshutlimitswitchwillcausedamagetothelimitswitchgearing,butwillnotpreventthevalvesfromclosing.ToassurethattheHV-G33-2F001, HV-G33-2F004, HV-B21-2F016 andHV-B21-2F019 valvesmeettheirminimumperformance requirements withimpressed voltagefaultsontheircomputerinputcables,thecomputerinputlimitswitchesshouldberewiredsuchthatthesevalveschangepositions andmeettheirminimumperformance requirements beforethecomputerinputswitchesareexposedtopotential welding.Therewiredvalvelimitswitchesshouldbenormallyopenandclosedonlywhen'thevalvesare100%closed(i.e.switchclosedwhenthevalvesclosedintheprimarycontainment isolation position).
ThisactionisbeingtrackedbyNCR87-0021.REFERENCES 6.1IEEE279-1971.
6.2IEEE384-1974.
6.3Regulatory Guide1.75,Rev.0.6.4Susquehanna SESUnit2I/OSpecification Listingdated'ec.
8,1989.6.5Susquehanna SESMotor-Operator ValveIndexdatedOct.17,1989.6.6SEA-EE-183, Rev.0.6.7Susquehanna SESDesignDescription ManualChapter5,15and31.jpa/rpa042i(18)
~~Iv SEA-EE-226 Page6of6TABLE1AFFILIATED MOTOR-OPERATED VALVESHY-821-2F001 HV-821-2F002 HV-821-2F005 HV-831-2F023A HV-831-2F0238 HV-831-2F031A HV-831-2F0318 HV-831-2F032A HV-831-2F0328 TABLE2MOTOR-OPERATED VALVESNOAUTOMATIC OPERATION HV-01112A HV-011128 HV-01112C HV-01112D HV-01110A HV-011108 HV-01110C HV-011100 HV-01122A HV-011228 HV-01122C HV-01122DHV-01120A HV-011208 HV-01120C HV-011200 HV-01112E HV-01122EHV-821-2F020 HV-G33-2F042 HV-G33-2F104 HV-24182A HV-241828 jpa/rpa042i (18) r~~~~~<<f>>4
