Information Notice 1994-58, Reactor Coolant Pump Lube Oil Fire

Reactor Coolant Pump Lube Oil Fire

ML031060498
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:	08/16/1994
From:	Grimes B K Office of Nuclear Reactor Regulation
To:
References
IN-94-058, NUDOCS 9408100058
Download: ML031060498 (9)

lQUNITED STATES C,NUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555August 16, 1994NRC INFORMATION NOTICE 94-58: REACTOR COOLANT PUMP LUBE OIL FIRE

Addressees

All holders of operating licenses or construction permits for pressurized-water reactors.PurnoseThe U.S. Nuclear Regulatory Commission (NRC) is issuing this informationnotice to alert addressees to a problem that may exist with the oil collectionsystem for the lube oil system components of reactor coolant pumps. It isexpected that recipients will review the information for applicability totheir facilities and consider actions, as appropriate, to avoid similarproblems. However, suggestions contained in this information notice are notNRC requirements; therefore, no specific action or written response isrequired.DescriDtion of CircumstancesHaddam Neck PlantOn July 11, 1994, while operating at 100 percent power, the licensee for theHaddam Neck Plant received a low oil level alarm for the upper lube oilreservoir of reactor coolant pump No. 3. The licensee later observed that theupper bearing temperature for reactor coolant pump No. 3 had been increasingfor approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> prior to receiving the low oil level alarm andreached 82 *C [180 OF]. The licensee began a controlled power reduction tobring the plant to a power level condition which would allow the reactorcoolant pump to be taken out of service. Simultaneously, a maintenance crewwas entering containment to fill the oil reservoir. Upon enteringcontainment, the maintenance crew observed smoke Just inside the airlock. Atthis time, the upper bearing temperature reached nearly 93 *C [200 OF], andthe licensee manually tripped the reactor from approximately 50 percent power.The heat detectors installed above the reactor coolant pump went into alarmapproximately 50 minutes later. At about the same time, the fire brigadeentered containment and reported a fire in the insulation around the pumpcasing and nearby piping of reactor coolant pump No. 3. The fire brigaderemoved insulation and extinguished the fire using portable dry chemical fireextinguishers. A relief crew later observed a reflash on the remaininginsulation, removed this insulation, and extinguished the second fire.The licensee determined that the oil leak and subsequent fire resulted from acrack in a 1-inch diameter, schedule 80, threaded PVC fitting in the pump lubeoil system. The PVC fitting was installed between the reactor coolant pump9408100058 P' JTT-i-E f'I' TXK 7i* -I1c -

v @ j 4-58Yugust 16, 1994 oil reservoir and the oil lift pump to electrically isolate the oil lift pumpfrom the reactor coolant pump motor. The oil leaking from the crack was notproperly collected and routed away from high velocity cooling air, which blewthe oil onto the insulation on the pump casing and pipe. The cooling air camefrom the reactor coolant pump motor and the area ventilation system. The hightemperature of the reactor coolant system (approximately 282 C [540 *F])ignited the oil-soaked insulation. (The flash point of the lube oil isapproximately 204 'C [400 'F].) The reservoir retained about 455 liters[120 gallons] of the approximately 755 liters (200 gallons] of oil originallyin the reservoir. About about 150 liters (40 gallons] of oil was collected bythe oil collection system, and 150 liters [40 gallons] leaked onto theinsulation and the containment floor.Millstone Nuclear Power Station. Unit 2On July 27, 1994, the lube oil low flow alarm for the 'A' reactor coolant pumpannunciated at Millstone Unit 2. Plant operators began reducing reactor powerin accordance with plant procedures. Licensee personnel inspected all of thereactor coolant pumps and found that oil had dripped from the tops of the 'A'and 'D' pump motors, coating the outside of the motors. Most of the oil wascontained by the oil collection drip pans; however, some of the oil thatleaked from the 'A' pump motor was not contained. Based on the observed firehazard in containment, the licensee shut down the plant.After the plant was shut down, an NRC inspector examined the lube oilcollection system and the area around the reactor coolant pumps. There were anumber of small oil leaks on each pump motor although there was more leakagefrom the 'A' pump motor. The inspector observed that various equipment aroundthe 'A' reactor coolant pump was coated with a film of oil and he estimatedthat several gallons of oil had collected in various areas outside the oilcollection system. The inspector also noted that portions of the lube oilsystem were outside the oil collection system and that the collection systempiping did not appear to be large enough to accommodate the largest potentialoil leak.DiscussionIn pressurized-water reactors, each reactor coolant pump motor typicallycontains between 530 and 830 liters [140 and 220 gallons) of oil. Oil leakingfrom the lube oil system may come in contact with either (1) surfaces that arehot enough to ignite the oil, or (2) an electrical source of ignition.Appendix R to Part 50 of Title 10 of the Code of Federal Regulations requiresthe installation of an oil collection system to collect oil from all potentialpressurized and unpressurized leakage sites. An adequately designed,installed, and maintained oil collection system is necessary to contain anyoil released because of leakage or failure of the lubrication system and tominimize fire hazards by draining the oil to a safe location.There are a number of differences between the reactor coolant pump motors andtheir associated lube oil systems at Millstone Unit 2 and Haddam Neck. Forexample, the Millstone Unit 2 motors do not use PVC or other syntheticcouplings in the lube oil system. The Millstone Unit 2 reactor coolant pump V <\,AN 94-58August 16, 1994 motors are manufactured by General Electric Company while the motors at HaddamNeck are manufactured by Westinghouse Electric Corporation. However, the oilcollection systems at the two plants are similar.The Haddam Neck oil collection system is intended to collect lube oil from allpotential leakage sites and to drain it to a vented, closed container toprevent a fire during normal conditions or design basis accident conditions.However, in this event the catch pan design, which relied on an unshieldedvertical flow of oil, was not adequate. This design allowed the air flowaround the motor to affect the vertical movement of the dripping oil andallowed it to escape the collection system. To a lesser extent, theventilation system also created air currents in the vicinity of the pump,which prevented some of the oil from being collected.The licensee is installing a steel dielectric union on each reactor coolantpump motor at Haddam Neck to replace the PVC fitting which failed and causedthe leak in this event. The licensee is also modifying the oil collectionsystem to account for air currents near the reactor coolant pumps.The ventilation system for the Millstone Unit 2 containment does notcontribute to the air flow around the reactor coolant pump motors. The onlyair flow in this area is caused by the motor itself. In addition, MillstoneUnit 2 has installed mirror insulation on some of the piping in the vicinityof the reactor coolant pumps. This type of insulation would prevent oil fromcoming in contact with and igniting on the high temperature piping itinsulates. These factors reduce, but do not eliminate, the likelihood ofleaking lube oil reaching an ignition source. However, the design of theexisting oil collection system was inadequate to contain existing andpotential oil leakage paths. The licensee is evaluating modifications thatcan be installed during the current forced outage to ensure that the lube oilcollection system for the reactor coolant pump motors meets the requirementsof Appendix R.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, DirectorDivision of Operating Reactor SupportOffice of Nuclear Reactor RegulationTechnical contacts: Edward A. Connell, NRR(301) 504-2838Ralph J. Paolino, RI(610) 337-5285

Attachment:

List of Recently Issued NRC Information Notices Att&,.AentIN 94-58August 16, 1994 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESInformation Date ofNotice No. Subject Issuance Issued to94-5794-5694-5591-79,Supp. 1Debris in Containmentand the Residual HeatRemoval SystemInaccuracy of Safety ValveSet Pressure DeterminationsUsing Assist DevicesProblems with Copes-Vulcan PressurizerPower-Operated ReliefValvesDeficiencies Found inThermo-Lag Fire BarrierInstallationFailures of GeneralElectric Magne-BlastCircuit Breakers toLatch ClosedPossible Malfunction ofWestinghouse ARD, BFD,and NBFD Relays, andA200 DC and DPC 250Magnetic Contactors08/12/9408/11/9408/04/9408/04/9408/01/9407/29/94All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.94-5491-45,Supp. 194-42,Supp. 1Cracking in the LowerRegion of the Core Shroudin Boiling-Water Reactors07/19/94All holdersfor boiling(BWRs).of OLs or CPswater reactors94-5394-52Hydrogen Gas Burn InsidePressurizer During WeldingInadvertent ContainmentSpray and Reactor VesselDraindown at MillstoneUnit 107/18/9407/15/94All holders of OLs or CPsfor nuclear power reactors.All holders of OLs or CPsfor nuclear power reactors.OL -Operating LicenseCP -Construction Permit IJN 94-58August 16, 1994 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. GrimesBrian K. Grimes, DirectorDivision of Operating Reactor SupportOffice of Nuclear Reactor RegulationTechnical contacts:Edward A. Connell, NRR(301) 504-2838Ralph J. Paolino, RI(610) 337-5285

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List of Recently Issued NRC Information NoticesrnL'- P -fiicAI-*See previous*SPLB:DSSAEAConnell07/21/94concurrence*DRS:RIRJPaolino07/21/94*OGCB:DORSPCWen07/21/94*TECH EDJMain07/21/94*SC/DSP:RIWHRuland07/21/94*C/OEAB:DORSAEChaffee07/26/94*SC/SPLB:DSSASKWest07/21/94*AC/OGCB:DORSElDoolittle07/28/94*C/SPLB:DSSACEMcCRACKEN07/2Z19402/*AD/DSSAMJVirgil io07/25/9408//o/94OFFICIAL RECORD COPYDOCUMENT NAME:94-58. INNOTES:* The PM was informed of the development of this Infor. Notice.* The licensee was consulted with the technical content of thisInfor. Notice, and its comments were incorporated. Subsequently,the final version was shown to R. Paolino (RI) and P. Madden (SPLB).They have no further comments.* This version also addressed OEAB's comment \_J IN 94-xxAugust xx, 1994 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, DirectorDivision of Operating Reactor SupportOffice of Nuclear Reactor RegulationTechnical contacts: Edward A. Connell, NRR(301) 504-2838Ralph J. Paolino, RI(610) 337-5285

Attachment:

List of Recently Issued NRC Information Notices*See previous*SPLB:DSSAEAConnell07/21/94concurrence*DRS:RIRJPaolano07/21/94*OGCB: DORSPCWen07/21/94*TECH EDJMain07/21/94*SC/DSP:RIWHRuland07/21/94*SC/SPLB:DSSASKWest07/21/94*C/SPLB:DSSACEMcCRACKEN07/22/94*AD/DSSAMJVirgilio07/25/94*C/OEAB:DORSAEChaffee07/26/94*AC/OGCB:DORSELDoolittle07/28/94D/DORSBKGrimes9fL08/ /94 vOFFICIAL RECORD COPYDOCUMENT NAME:HADMNECK.INNOTES:* The PM was informed of the development of this Infor. Notice.* The licensee was consulted with the technical content of thisInfor. Notice, and its comments were incorporated. Subsequently,the final version was shown to R. Paolino (RI) and P. Madden (SPLB).They have no further comments.* This version also addressed OEAB's comment '->IN 94-xxJuly xx, 1994 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, DirectorDivision of Operating Reactor SupportOffice of Nuclear Reactor RegulationTechnical contacts:Edward A. Connell, NRR(301) 504-2838Ralph J. Paolino,RI(610) 337-5285

Attachment:

List of Recently Issued NRC Information Notices*See previous*SPLB:DSSAEAConnell07/21/94concurrence*DRS:RIRJPaolino07/21/94*OGCB:DORSPCWen07/21/94*TECH EDJMain07/21/94*SC/DSP:RIWHRuland07/21/94*SC/SPLB:DSSASKWest07/21/94AC RSE le*C/SPLB:DSSACEMcCRACKEN07/22/94*AD/DSSAMJVirgilio07/25/94*C/OEAB:DORSAEChaffee07/26/94D/DORSBKGrimes07/ /941,0-wOFFICIAL RECORD COPYDOCUMENT NAME: HADMNECK.INNOTES:* The PM was informed of the development of this Infor.* The licensee was consulted with the technical contentInfor. Notice, and its comments were incorporated. Sithe final version was shown to R. Paolino (RI) and P.They have no further comments.* This version also addressed OEAB's comments.Notice.of thisubsequently,Madden (SPLB)~t. 7A/94

'JIN 94-xxJuly xx, 1994 The licensee is considering flanged connections to replace the PVC fittings.The licensee is also modifying the oil collection system to account for theair currents near the RCPs.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, DirectorDivision of Operating Reactor SupportOffice of Nuclear Reactor RegulationTechnical contacts:Edward A. Connell, NRR(301) 504-2838Ralph J. Paolino,RI(610) 337-5285

Attachment:

List of Recently Issued NRC Information Notices*See previous concurrence*SPLB:DSSA *DRS:RIEAConnell RJPaolino07/21/94 07/21/94*SC/DSP:RI *SC/SPLB:DSSAWHRuland SKWest07/21/94 07/21/94C G l ORS AC/OGCB:DORSA0a ffee ELDoolittle07/A/94 07/ /94OFFICIAL RECORD COPY*OGCB:DORSPCWen" P DSACEMcCRACKEN07/Ap94 sD/DORSBKGrimes07/ /94*TECH EDJMain07/21/94AD/DSSAOA 'MJVirqilio07/$6/94DOCUMENT NAME:HADNECK.RI V',-AN 94-xxJuly xx, 1994 The licensee is considefing flanged connections to replace the PVC fittings.The licensee is also modifying the oil collection system to account for theair currents near the RCPs.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, DirectorDivision of Operating Reactor SupportOffice of Nuclear Reactor RegulationTechnical contacts:Edward A. Connell, NRR(301) 504-2838Ralph(610)J. Paolino,RI337-5285

Attachment:

List of Recently Issued NRC Information NoticesSPLB:DSSAEAConnell07/Z/ /94SC/DSP: RWHRul and-8 07/%1/94C/OEAB:DORSAEChaffee07/ /94DRS:RIRJPaol ino07 I/94SKWest07/t- /94AC/OGCB:DORSELDoolittle07/ /94OGCB:gQRSPCWen 1-07,l1/94C/SPLB:DSSACEMcCRACKEN07/ /94TECH EDJMain asp07/21/94AD/DSSAMJVirgilio07/ /94D/DORSBKGrimes07/ /94OFFICIAL RECORD COPYDOCUMENT NAME:HADNECK.RI