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 Office of Nuclear Reactor Regulation
To:
References
IN-94-058, NUDOCS 9408100058
Download: ML031060498 (9)

lQ UNITED STATES C, NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 August 16, 1994 NRC INFORMATION

NOTICE 94-58: REACTOR COOLANT PUMP LUBE OIL FIRE

Addressees

All holders of operating

licenses or construction

permits for pressurized- water reactors.Purnose The U.S. Nuclear Regulatory

Commission (NRC) is issuing this information

notice to alert addressees

to a problem that may exist with the oil collection

system for the lube oil system components

of reactor coolant pumps. It is expected that recipients

will review the information

for applicability

to their facilities

and consider actions, as appropriate, to avoid similar problems.

However, suggestions

contained

in this information

notice are not NRC requirements;

therefore, no specific action or written response is required.DescriDtion

of Circumstances

Haddam Neck Plant On July 11, 1994, while operating

at 100 percent power, the licensee for the Haddam Neck Plant received a low oil level alarm for the upper lube oil reservoir

of reactor coolant pump No. 3. The licensee later observed that the upper bearing temperature

for reactor coolant pump No. 3 had been increasing

for 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 and reached 82 *C [180 OF]. The licensee began a controlled

power reduction

to bring the plant to a power level condition

which would allow the reactor coolant pump to be taken out of service. Simultaneously, a maintenance

crew was entering containment

to fill the oil reservoir.

Upon entering containment, the maintenance

crew observed smoke Just inside the airlock. At this time, the upper bearing temperature

reached nearly 93 *C [200 OF], and the licensee manually tripped the reactor from approximately

50 percent power.The heat detectors

installed

above the reactor coolant pump went into alarm approximately

50 minutes later. At about the same time, the fire brigade entered containment

and reported a fire in the insulation

around the pump casing and nearby piping of reactor coolant pump No. 3. The fire brigade removed insulation

and extinguished

the fire using portable dry chemical fire extinguishers.

A relief crew later observed a reflash on the remaining insulation, removed this insulation, and extinguished

the second fire.The licensee determined

that the oil leak and subsequent

fire resulted from a crack in a 1-inch diameter, schedule 80, threaded PVC fitting in the pump lube oil system. The PVC fitting was installed

between the reactor coolant pump 9408100058 P' JTT-i-E f'I' TXK 7i* -I1c -

v @ j 4-58 Yugust 16, 1994 oil reservoir

and the oil lift pump to electrically

isolate the oil lift pump from the reactor coolant pump motor. The oil leaking from the crack was not properly collected

and routed away from high velocity cooling air, which blew the oil onto the insulation

on the pump casing and pipe. The cooling air came from the reactor coolant pump motor and the area ventilation

system. The high temperature

of the reactor coolant system (approximately

282 C [540 *F])ignited the oil-soaked

insulation. (The flash point of the lube oil is approximately

204 'C [400 'F].) The reservoir

retained about 455 liters[120 gallons] of the approximately

755 liters (200 gallons] of oil originally

in the reservoir.

About about 150 liters (40 gallons] of oil was collected

by the oil collection

system, and 150 liters [40 gallons] leaked onto the insulation

and the containment

floor.Millstone

Nuclear Power Station. Unit 2 On July 27, 1994, the lube oil low flow alarm for the 'A' reactor coolant pump annunciated

at Millstone

Unit 2. Plant operators

began reducing reactor power in accordance

with plant procedures.

Licensee personnel

inspected

all of the reactor 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 was contained

by the oil collection

drip pans; however, some of the oil that leaked from the 'A' pump motor was not contained.

Based on the observed fire hazard in containment, the licensee shut down the plant.After the plant was shut down, an NRC inspector

examined the lube oil collection

system and the area around the reactor coolant pumps. There were a number of small oil leaks on each pump motor although there was more leakage from the 'A' pump motor. The inspector

observed that various equipment

around the 'A' reactor coolant pump was coated with a film of oil and he estimated that several gallons of oil had collected

in various areas outside the oil collection

system. The inspector

also noted that portions of the lube oil system were outside the oil collection

system and that the collection

system piping did not appear to be large enough to accommodate

the largest potential oil leak.Discussion

In pressurized-water

reactors, each reactor coolant pump motor typically contains between 530 and 830 liters [140 and 220 gallons) of oil. Oil leaking from the lube oil system may come in contact with either (1) surfaces that are hot 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

requires the installation

of an oil collection

system to collect oil from all potential pressurized

and unpressurized

leakage sites. An adequately

designed, installed, and maintained

oil collection

system is necessary

to contain any oil released because of leakage or failure of the lubrication

system and to minimize fire hazards by draining the oil to a safe location.There are a number of differences

between the reactor coolant pump motors and their associated

lube oil systems at Millstone

Unit 2 and Haddam Neck. For example, the Millstone

Unit 2 motors do not use PVC or other synthetic couplings

in the lube oil system. The Millstone

Unit 2 reactor coolant pump

V <\,AN 94-58 August 16, 1994 motors are manufactured

by General Electric Company while the motors at Haddam Neck are manufactured

by Westinghouse

Electric Corporation.

However, the oil collection

systems at the two plants are similar.The Haddam Neck oil collection

system is intended to collect lube oil from all potential

leakage sites and to drain it to a vented, closed container

to prevent a fire during normal conditions

or design basis accident conditions.

However, in this event the catch pan design, which relied on an unshielded

vertical flow of oil, was not adequate.

This design allowed the air flow around the motor to affect the vertical movement of the dripping oil and allowed it to escape the collection

system. To a lesser extent, the ventilation

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 coolant pump motor at Haddam Neck to replace the PVC fitting which failed and caused the leak in this event. The licensee is also modifying

the oil collection

system to account for air currents near the reactor coolant pumps.The ventilation

system for the Millstone

Unit 2 containment

does not contribute

to the air flow around the reactor coolant pump motors. The only air flow in this area is caused by the motor itself. In addition, Millstone Unit 2 has installed

mirror insulation

on some of the piping in the vicinity of the reactor coolant pumps. This type of insulation

would prevent oil from coming in contact with and igniting on the high temperature

piping it insulates.

These factors reduce, but do not eliminate, the likelihood

of leaking lube oil reaching an ignition source. However, the design of the existing oil collection

system was inadequate

to contain existing and potential

oil leakage paths. The licensee is evaluating

modifications

that can be installed

during the current forced outage to ensure that the lube oil collection

system for the reactor coolant pump motors meets the requirements

of Appendix R.This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating

Reactor Support Office of Nuclear Reactor Regulation

Technical

contacts:

Edward A. Connell, NRR (301) 504-2838 Ralph J. Paolino, RI (610) 337-5285 Attachment:

List of Recently Issued NRC Information

Notices

Att&,.Aent

IN 94-58 August 16, 1994 LIST OF RECENTLY ISSUED NRC INFORMATION

NOTICES Information

Date of Notice No. Subject Issuance Issued to 94-57 94-56 94-55 91-79, Supp. 1 Debris in Containment

and the Residual Heat Removal System Inaccuracy

of Safety Valve Set Pressure Determinations

Using Assist Devices Problems with Copes-Vulcan Pressurizer

Power-Operated

Relief Valves Deficiencies

Found in Thermo-Lag

Fire Barrier Installation

Failures of General Electric Magne-Blast

Circuit Breakers to Latch Closed Possible Malfunction

of Westinghouse

ARD, BFD, and NBFD Relays, and A200 DC and DPC 250 Magnetic Contactors

08/12/94 08/11/94 08/04/94 08/04/94 08/01/94 07/29/94 All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.94-54 91-45, Supp. 1 94-42, Supp. 1 Cracking in the Lower Region of the Core Shroud in Boiling-Water

Reactors 07/19/94 All holders for boiling (BWRs).of OLs or CPs water reactors 94-53 94-52 Hydrogen Gas Burn Inside Pressurizer

During Welding Inadvertent

Containment

Spray and Reactor Vessel Draindown

at Millstone Unit 1 07/18/94 07/15/94 All holders of OLs or CPs for nuclear power reactors.All holders of OLs or CPs for nuclear power reactors.OL -Operating

License CP -Construction

Permit

IJN 94-58 August 16, 1994 This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Original signed by Brian K. Grimes Brian K. Grimes, Director Division of Operating

Reactor Support Office of Nuclear Reactor Regulation

Technical

contacts: Edward A. Connell, NRR (301) 504-2838 Ralph J. Paolino, RI (610) 337-5285 Attachment:

List of Recently Issued NRC Information

Notices rnL'- P -fiicAI-*See previous*SPLB:DSSA

EAConnell 07/21/94 concurrence

• DRS:RI RJPaolino 07/21/94*OGCB:DORS

PCWen 07/21/94*TECH ED JMain 07/21/94*SC/DSP:RI

WHRuland 07/21/94*C/OEAB:DORS

AEChaffee 07/26/94*SC/SPLB:DSSA

SKWest 07/21/94*AC/OGCB:DORS

ElDoolittle

07/28/94*C/SPLB:DSSA

CEMcCRACKEN

07/2Z19402/

• AD/DSSA MJVirgil io 07/25/94 08//o/94 OFFICIAL RECORD COPY DOCUMENT NAME: 94-58. IN NOTES:* The PM was informed of the development

of this Infor. Notice.* The licensee was consulted

with the technical

content of this Infor. 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 comments.

\_J IN 94-xx August xx, 1994 This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating

Reactor Support Office of Nuclear Reactor Regulation

Technical

contacts:

Edward A. Connell, NRR (301) 504-2838 Ralph J. Paolino, RI (610) 337-5285 Attachment:

List of Recently Issued NRC Information

Notices*See previous*SPLB:DSSA

EAConnell 07/21/94 concurrence

• DRS:RI RJPaolano 07/21/94*OGCB: DORS PCWen 07/21/94*TECH ED JMain 07/21/94*SC/DSP:RI

WHRuland 07/21/94*SC/SPLB:DSSA

SKWest 07/21/94*C/SPLB:DSSA

CEMcCRACKEN

07/22/94*AD/DSSA MJVirgilio

07/25/94*C/OEAB:DORS

AEChaffee 07/26/94*AC/OGCB:DORS

ELDoolittle

07/28/94 D/DORS BKGrimes9fL

08/ /94 v OFFICIAL RECORD COPY DOCUMENT NAME: HADMNECK.IN

NOTES:* The PM was informed of the development

of this Infor. Notice.* The licensee was consulted

with the technical

content of this Infor. 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 comments.

'->IN 94-xx July xx, 1994 This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating

Reactor Support Office of Nuclear Reactor Regulation

Technical

contacts: Edward A. Connell, NRR (301) 504-2838 Ralph J. Paolino,RI

(610) 337-5285 Attachment:

List of Recently Issued NRC Information

Notices*See previous*SPLB:DSSA

EAConnell 07/21/94 concurrence

• DRS:RI RJPaolino 07/21/94*OGCB:DORS

PCWen 07/21/94*TECH ED JMain 07/21/94*SC/DSP:RI

WHRuland 07/21/94*SC/SPLB:DSSA

SKWest 07/21/94 AC RS E le*C/SPLB:DSSA

CEMcCRACKEN

07/22/94*AD/DSSA MJVirgilio

07/25/94*C/OEAB:DORS

AEChaffee 07/26/94 D/DORS BKGrimes 07/ /94 1,0-w OFFICIAL RECORD COPY DOCUMENT NAME: HADMNECK.IN

NOTES:* The PM was informed of the development

of this Infor.* The licensee was consulted

with the technical

content Infor. Notice, and its comments were incorporated.

Si the final version was shown to R. Paolino (RI) and P.They have no further comments.* This version also addressed

OEAB's comments.Notice.of this ubsequently, Madden (SPLB)~t. 7A/94

'JIN 94-xx July 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 the air currents near the RCPs.This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating

Reactor Support Office of Nuclear Reactor Regulation

Technical

contacts: Edward A. Connell, NRR (301) 504-2838 Ralph J. Paolino,RI

(610) 337-5285 Attachment:

List of Recently Issued NRC Information

Notices*See previous concurrence

• SPLB:DSSA

• DRS:RI EAConnell

RJPaolino 07/21/94 07/21/94*SC/DSP:RI

• SC/SPLB:DSSA

WHRuland SKWest 07/21/94 07/21/94 C G l ORS AC/OGCB:DORS

A0a ffee ELDoolittle

07/A/94 07/ /94 OFFICIAL RECORD COPY*OGCB:DORS

PCWen" P DSA CEMcCRACKEN

07/Ap94 s D/DORS BKGrimes 07/ /94*TECH ED JMain 07/21/94 AD/DSSAOA

'MJVirqilio

07/$6/94 DOCUMENT NAME: HADNECK.RI

V',-AN 94-xx July 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 the air currents near the RCPs.This information

notice requires no specific action or written response.

If you have any questions

about the information

in this notice, please contact one of the technical

contacts listed below or the appropriate

Office of Nuclear Reactor Regulation (NRR) project manager.Brian K. Grimes, Director Division of Operating

Reactor Support Office of Nuclear Reactor Regulation

Technical

contacts: Edward A. Connell, NRR (301) 504-2838 Ralph (610)J. Paolino,RI

337-5285 Attachment:

List of Recently Issued NRC Information

Notices SPLB:DSSA EAConnell 07/Z/ /94 SC/DSP: R WHRul and-8 07/%1/94 C/OEAB:DORS

AEChaffee 07/ /94 DRS:RI RJPaol ino 07 I/94 SKWest 07/t- /94 AC/OGCB:DORS

ELDoolittle

07/ /94 OGCB:gQRS PCWen 1-07,l1/94 C/SPLB:DSSA

CEMcCRACKEN

07/ /94 TECH ED JMain asp 07/21/94 AD/DSSA MJVirgilio

07/ /94 D/DORS BKGrimes 07/ /94 OFFICIAL RECORD COPY DOCUMENT NAME: HADNECK.RI