Information Notice 1996-24, Preconditioning of Molded-Case Circuit Breakers Before Surveillance Testing

Preconditioning of Molded-Case Circuit Breakers Before Surveillance Testing

ML031060110
Person / Time
Site:	Beaver Valley, Millstone, Hatch, Monticello, Calvert Cliffs, Dresden, Davis Besse, Peach Bottom, Browns Ferry, Salem, Oconee, Mcguire, Nine Mile Point, Palisades, Palo Verde, Perry, Indian Point, Fermi, Kewaunee, Catawba, Harris, Wolf Creek, Saint Lucie, Point Beach, Oyster Creek, Watts Bar, Hope Creek, Grand Gulf, Cooper, Sequoyah, Byron, Pilgrim, Arkansas Nuclear, Three Mile Island, Braidwood, Susquehanna, Summer, Prairie Island, Columbia, Seabrook, Brunswick, Surry, Limerick, North Anna, Turkey Point, River Bend, Vermont Yankee, Crystal River, Haddam Neck, Ginna, Diablo Canyon, Callaway, Vogtle, Waterford, Duane Arnold, Farley, Robinson, Clinton, South Texas, San Onofre, Cook, Comanche Peak, Yankee Rowe, Maine Yankee, Quad Cities, Humboldt Bay, La Crosse, Big Rock Point, Rancho Seco, Zion, Midland, Bellefonte, Fort Calhoun, FitzPatrick, McGuire, LaSalle, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date:	04/25/1996
Revision:	0
From:	Grimes B K Office of Nuclear Reactor Regulation
To:
References
IN-96-024, NUDOCS 9604220229
Download: ML031060110 (14)

April 25, 1996

NRC INFORMATION NOTICE 96-24: PRECONDITIONING OF MOLDED-CASE CIRCUIT BREAKERSBEFORE SURVEILLANCE TESTING

Addressees

All holders of operating licenses or construction permits for nuclear powerreactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is issuing this informationnotice to alert addressees to the detrimental effect that preconditioning ofmolded-case circuit breakers could have on the diagnostic validity ofsurveillance tests. It is expected that recipients will review thisinformation for applicability to their facilities and consider actions, asappropriate, to avoid similar problbms. However, suggestions contained inthis information notice are not NRC requirements; therefore, no specificaction or written response is required.DescriDtion of CircumstancesDuring an inspection at the Diablo Canyon Nuclear Power Plant (IR 50-275,323/94-27 dated December 21, 1994), NRC inspectors noted that the licenseepreconditioned circuit breakers before performing surveillance testing.Before the overcurrent trip testing, Diablo Canyon staff exercised the circuitbreakers by manually opening and closing them three times. The plant staff'did not record the as-found condition of the breakers in terms of unexercisedtrip currents and times.During another inspection at the South Texas Project (IR 50-498, 499/94-35dated January 19, 1995), NRC inspectors noted that the licensee exercisedsimilar circuit breakers manually at least five times before testing theovercurrent trip unit.DiscussionA molded-case circuit breaker is one of the most widely used protectivedevices for electrical circuits at nuclear power plants. Its proper operationis essential for the protection and safe operation of plant electricalequipment. Many circuit breakers are continuously energized for long periods.Often they are in service for years and are rarely, if ever, called upon toperform a protective function. Nevertheless, when needed, they must rapidlyisolate a faulted or overloaded circuit to prevent equipment damage.Therefore, for the safe operation of the electrical distribution systemequipment of a nuclear power plant, it is important to periodically verifytheir continued reliability..K VE uor~cEya-0OZ %6qZ 'I K>IIN 96-24April 25, 1996 Periodic inspection and testing of circuit breakers in their as-foundcondition is an appropriate way of demonstrating the functional operability ofthe breaker and of detecting any degradation. However, the practice ofpreconditioning before testing (e.g., lubricating pivot points and manuallycycling the breaker) defeats the purpose of the periodic test. Suchpreconditioning does not confirm continued operability between tests nor doesit provide information on the condition of the circuit breaker for trendingpurposes. Testing some circuit breakers in the as-found condition can provideuseful data on which to base decisions on surveillance intervals and theability of the untested circuit breakers to perform their intended function.Since only a fraction of the circuit breakers are tested each refueling outageto justify the operability of the remaining circuit breakers, preconditioningbefore testing does not provide the expected assurance of the operability ofremaining breakers which are not tested. By preconditioning circuit breakers,useful information may be lost because the breaker may not have been capableof performing its intended function without preconditioning.To correct this situation, Diablo Canyon Power Plant plans to revise theelectrical maintenance procedure before the next surveillance test has to beperformed. The revised procedures will state that electrical testing shouldbe performed before any intentional manual exercising of the breakers, and toensure that electrical testing on breakers with removable trip units isperformed before removing the trip unit.Some plants have older technical specification bases that cite NationalElectrical Manufacturers Association (NEMA) Standard AB 2-1980. This versionof the standard specifies mechanical cycling of circuit breakers prior toelectrical testing. In later versions of this standard, this procedure wasdeleted. There appears to be no valid technical need for mechanical cyclingprior to electrical surveillance testing.The NRC has issued other generic communications on molded-case circuit breakerapplications and testing: NRC Information Notice (IN) 92-51, and itsSupplement 1, "Misapplication and Inadequate Testing of Molded-Case CircuitBreakers;" IN 93-26, "Grease Solidification Causes Molded Case Circuit BreakerFailure to Close;" and IN 93-64, "Periodic Testing and Preventive Maintenanceof Molded-Case Circuit Breakers."

If IIN 96-24April 25, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager. /aL.."Brian K. Grimes, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Sikhindra Mitra, NRR(301) 415-2783Internet:skml@nrc.govSteve Alexander, NRR(301) 415-2995Internet:sda@nrc.govChristopher Myers, RIV(817) 860-8144Internet:cjm@nrc.gov

Attachment:

List of Recently Issued NRC Information Notices-tw@ / "Y KAttachmentIN 96-24April 25, 1996 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to96-2396-2296-2196-20Fires in Emergency DieselGenerator Exciters DuringOperation Following Unde-tected Fuse BlowingImproper Equipment Set-tings Due to the Use ofNontemperature-CompensatedTest EquipmentSafety Concerns Relatedto the Design of the DoorInterlock Circuit onNucletron High-Dose Rateand Pulsed Dose RateRemote AfterloadingBrachytherapy DevicesDemonstration of Associ-ated Equipment Compliancewith 10 CFR 34.20Failure of Tone AlertRadios to Activate WhenReceiving a ShortenedActivation SignalCompliance with 10 CFRPart 20 for AirborneThoriumLoss of Reactor CoolantInventory and PotentialLoss of Emergency Mitiga-tion Functions While in aShutdown Condition04/22/9604/11/9604/10/9604/04/9604/02/9603/25/9603/25/96All holders of OLs or CPsfor nuclear power reactorsAll holders of OLs or CPsfor nuclear power reactorsAll U.S. NRC Medical to theLicensees authorized to usebrachytherapy sources inhigh- and pulsed-dose-rateremote afterloadersAll industrial radiographylicensees and radiographyequipment manufacturersAll holders of OLs or CPsfor nuclear power reactorsAll material licenseesauthorized to possess anduse thorium in unsealedformAll holders of OLs or CPsfor PWR power plants96-1996-1895-03Supp. 1OL = Operating LicenseCP -Construction Permit K2 2 IN 96-24April 25, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.original signed byBrian K. Grimes, Acting DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Sikhindra Mitra, NRR(301) 415-2783Internet:skml@nrc.govSteve Alexander, NRR(301) 415-2995Internet:sda@nrc.govChristopher Myers, RIV(817) 860-8144Internet:cjm@nrc.gov

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 96-24.IN Tech Editor reviewed 9/21/95To receive a copy of this document, Indicate In the box: 'C' -Copy without enclosures 'E" = Copy with sncloRre l -= No copyOFFICE Contacts C IEELBNAME CMyers

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• AChatfee sSMitra * /SAlexander* 7 ,DATE 4/22/96 4/15/96 4/22/96 4/LT/96OFFICIAL RECORD COPY IN 96-XXApril XX, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Dennis M. Crutchfield, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Sikhindra Mitra, NRR(301) 415-2783Internet: skmlnrc.govChristopher Myers, RIV(817) 860-8144Internet: cjm@nrc.govSteve Alexander, NRR(301) 415-2995Internet: sda@nrc.gov

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.INTo receive a copy of this document. Indicate In the box:Tech Editor reviewed 9/21/95'C' -Copy without enclosures fEw -Copy with enclosures 'N' -No copyOFFICE IContacts C/EELB I D/DRPI lNAME CMyers

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• AChaffee DCrutchfieldSMitra *SAlexanderLnfi_DATE 4 /15/96 7' 4/15/96 4/ /96 4/ /96.-------UICLIAL KECOKR COPY,44 I1 i< -' IN 96-XXApril XX, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Dennis M. Crutchfield, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Sikhindra Mitra, NRR(301) 415-2783Internet: skmlnrc.govChristopher Myers, RIV(817) 860-8144Internet: cjm~nrc.gov

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.IN Tech Editor reviewed 9/21/95To receive a copy of this document, Indicate In the box: 'C' -Copy without enclosures 'E' -Copy with enclosures 'No = No copylOFFICE Contacts I C/EELB l C/PECB I DRPM INAME CMyers

• JCalvo

• AChaffee DCrutchfieldSMitra *DATE 4 /I5/96 4/11 /96 4/ 4/ /96OFFICIAL RECORD COPY IN 96-XXApril XX, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Dennis M. Crutchfield, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Christopher Myers, RIV(817) 860-8144Sikhindra Mitra, NRR(301) 415-2783

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.IN Tech Editor reviewed 9/21/95To receive a copy of this document. Indicate In the box: wCw = Copy without enclosures 'E" -Copy with enclosures 'N'= No copyOFFICE Contacts C/EELB INAME Myers JCalvoJy r AChaffee DCrutchfieldI ~SMi tra_ _ _ _ _ _ _DATE 4 /16796 4/ I7 /96 4/ /96 4/ /96OFFICIAL RECORD COPY IN 96-XXApril xx, 1996 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Dennis M. Crutchfield, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Tom Westerman, RIV(817) 860-8145Christopher Myers, RIV(817) 860-8144Stephen Alexander, NRR(301) 415-2995Sikhindra Mitra, NRR(301) 415-2783

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.INT - 5 .LL.1. .I *k. i hn,.. tC = -Cnnu without enclosuresrcv

• wprs r^uumn, juciva lwi'Jw. --r,. ........................... ,* .See previous concurrence=E' CoDv with enclosures 'N' = No copyOFFICE RIV liE RIV E lRIV l E RIV E PSIB:DISP ENAME LTWesterman A CMyers k _ TP Gwyn* SAlexanderDATE I1 / g/95 t /, /95 / /95 01/25/95 / /95OFFICE TECH ED N SC:SIB:DISP l EE:DE E SC:EELB:DE E C:EELB:DEl ENAME WRSanders SKMitra 't ASGill* JACalvo*DATE 109/21/95* / /95 41,1/2o%96 I/Y.1 09/21/95 9/27/95OFFICE IPECB:DRPM PECB:DRPM PECB:DRPM I C:PECB:DRPM l D:DRPMNAME JTKoshy EFGoodwin* AChaffee DMCrutchfieldDATE IJ /f/96 10/04/95 I /95 /95 /95OFFICIAL RECORD COPY IN 96-XXJanuary xx, 1995 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Dennis M. Crutchfield, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Tom Westerman, RIV(817) 860-8145Christopher Myers, RIV(817) 860-8144Stephen Alexander, NRR(301) 415-2995Sikhindra Mitra,(301) 415-2783NRR

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.INTo receive a copv ol this document. indicate In the box: C -Coov without enclosures* .See previous concurrence-E' .CoDV with enclosures "N" -No coDYlOFFICE RI Tf RI E _I I BDSNAME TWesterman CMyers _ _ _ TP Gwyn* SAl exanderDATE / /95 1 I / /9 IL/5 01_/25/95 / /95OFFICE lTECH ED N SC:SIB:DISP E EELB:DE E SC:EELB:DE I E lC:EELB:DEl ENAME l RSanders SKMi tra ASGill* JJACalvo*DATE l09/21/95* / /95 I / 1/96 09/21/95 9/27/95OFFICE JIPECB:DRPM PECB:DRPM I C:PECB:DRPMl D:DRPMNAME TKoshy EFGoodwin* AChaffee DMCrutchfi eldDATE I /oF/9 _ 10/04/95 / /95 / /95 / /95OFFICIAL RECORD COPY IK 'IIN 95-XXSeptember xx, 995This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Dennis M. Crutchfield, DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical contacts:Tom Westerman, RIV(817) 860-8145Christopher Myers,(817) 860-8144RIVStephen Alexander, NRR(301) 415-2995Sikhindra Mitra, NRR(301) 415-2783

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.INTe raclva a etonw of thb document Indicate hI Om box: 'C' -Copv without enclosures*

• See previous concurrence'E -Copy with enclosures 'N- -No copyOFFICE R E RIV E R RIV E PSIB:DISP ENAME TWesterman c CMyers / T/5 6_ _ _w n SAlexanderDATE I /Teean/95 jC/1y/95 / /95 _ T/ZS/95 I /95OFFICE TECH ED N SC:SIB:DISP l DEE E SC:EELB:DE E C:EELB:DE ENAME RSanders SKMitra* ASGill* JACalvo*DATE 09/21/95* / /95 09/20/95 09/21/95 / /95OFFICE PECB:DRPM I E PECB:DRPM / l-JLIPEIBhRPM IZ C:PECB:DRPM ID:DRPMNAME TKoshy EFGoodwin RJK AChaffee DMCrutchfieldDATE 9/26/95 y 95 V // /95 / /95OFFICIAL RECORD COPY IN 95-XXSeptember xx, 1995 This information notice requires no specific action or written response. Ifyou have any questions about the information in this notice, please contactone of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Deputy DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts: Tom Westerman, RIV(817) 860-8145Christopher Myers, RIV(817) 860-8144Stephen Alexander, NRR(301) 415-2995Sikhindra Mitra, NRR(301) 415-2783

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.IN * , See previous concurrenceTo receive a copy of this document. Indicate In the box: 'C' Copy without enclosures E' -Copy with enclosures N -No copyOFFICE RIY I E RIY E RIYE RIV E PSIB:DISP ENAME TWesterman CMyers ____ _ SAlexanderDATE / /LE95 / /95 I /95 /95 / /95OFFICE TECH ED I N SC:SIB:DISP E EELB:DE I E SC:EELB:DEl E C:EELB:DEI ENAME RSanders SKMitra* ASGill* JACalvo I/ACjDATE 09/21/95* / /95 09/20/95 09/21/95 f /17/95 qI~d'3OFFICE PECB:DRPM l C:PECB:DRPM l DD:DRPMNAME AChaffee BKGrimesDATE I /95 / /95 l//95OFFICIAL RECORD COPY IN 95-XXAugust XX, 1995 one of the technical contacts listed below or the appropriate Office ofNuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Deputy DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts:Tom Westerman, RIV(817) 860-8145Christopher Myers, RIV(817) 860-8144Stephen Alexander, NRR(301) 415-2995Sikhindra Mitra, NRR(301) 415-2783

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.INa nv Cf thids donument. indicate In the box:* .See previous concurrence'C' -Coov without enclosures 'E' -Copy with enclosures 'N' .No copyTo rAceivAOFFICE RIV l1 El t E RE R E RIV I E lPSIB:DISP I ENAME TWesterman CMyers ISAlexanderDATE / /95 I /95 / /95 /95 /95OFFICE TECH ED N SC:SIB:DISP I E EELB:DE E SC:EELB-DE E C:EELB:DEl ENAME BCalure SKMitra YOM& ASGill t JACalvoDATE 08/03/95* j-/ /95 / O/95 /04/95 / /95OFFICE PECB:DRPM l C:PECB:DRPMT DD:DRPMNAME AChaffee BKGrimesDATE I /95 / /95 / /95OFFICIAL RECORD COPY K-/IN 95-XXAugust XX, 1995 one of the technical contacts listed below or theNuclear Reactor Regulation (NRR) project manager.appropriate Office ofBrian K. Grimes, Deputy DirectorDivision of Reactor Program ManagementOffice of Nuclear Reactor RegulationTechnical Contacts:Tom Westerman, RIV(817) 860-8145Christopher Myers, RIV(817) 860-8144Stephen Alexander, NRR(301). 415-2995Sikhindra Mitra, NRR(301) 415-2783

Attachment:

List of Recently Issued NRC Information NoticesDOCUMENT NAME: 95-XX.INTo receive a copy of this document. Indicate In the box:* = See previous concurrencewEd -Copy with oncosurss rW -No copyNCR -Copy without endosurmsOFFICE RIV I E RIY E RIV E RIV I E PSIB:DISP I ENAME TWesterman CMyers I jSAlexanderDATE / /95 / /95 1/. /95 /95 / /95OFFICE TECH ED N SC:SIB:DISP I E EELB:DE E SC:EELB:DE E C:EELB:DEI ENAME BCalure K54a" 1SKMitra ASGill JACalvo IDATE 08/03/95* gf(g fIq / /95 / /95 /95 / /95OFFICE PECB:DRPM C:PECB:DRPM DD:DRPMNAME 1AChaffee BKGrimes _ lDATE/ /95 1 / /95 / /95 IIOFFICIAL RECORD COPY