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 not

problems. However, suggestions contained in this information notice are

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 to

reached 82 *C [180 OF]. The licensee began a controlled power reduction

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.and At

this time, the upper bearing temperature reached nearly 93 *C [200 OF],

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 fire

removed insulation and extinguished the fire using portable dry chemical

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

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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 Debris in Containment 08/12/94 All holders of OLs or CPs

and the Residual Heat for nuclear power reactors.

Removal System

94-56 Inaccuracy of Safety Valve 08/11/94 All holders of OLs or CPs

Set Pressure Determinations for nuclear power reactors.

Using Assist Devices

94-55 Problems with Copes- 08/04/94 All holders of OLs or CPs

Vulcan Pressurizer for nuclear power reactors.

Power-Operated Relief

Valves

91-79, Deficiencies Found in 08/04/94 All holders of OLs or CPs

Supp. 1 Thermo-Lag Fire Barrier for nuclear power reactors.

Installation

94-54 Failures of General 08/01/94 All holders of OLs or CPs

Electric Magne-Blast for nuclear power reactors.

Circuit Breakers to

Latch Closed

91-45, Possible Malfunction of 07/29/94 All holders of OLs or CPs

Supp. 1 Westinghouse ARD, BFD, for nuclear power reactors.

and NBFD Relays, and

A200 DC and DPC 250

Magnetic Contactors

94-42, Cracking in the Lower 07/19/94 All holders of OLs or CPs

Supp. 1 Region of the Core Shroud for boiling water reactors

in Boiling-Water Reactors (BWRs).

94-53 Hydrogen Gas Burn Inside 07/18/94 All holders of OLs or CPs

Pressurizer During Welding for nuclear power reactors.

94-52 Inadvertent Containment 07/15/94 All holders of OLs or CPs

Spray and Reactor Vessel for nuclear power reactors.

Draindown at Millstone

Unit 1 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 concurrence

• SPLB:DSSA *DRS:RI *OGCB:DORS *TECH ED

EAConnell RJPaolino PCWen JMain

07/21/94 07/21/94 07/21/94 07/21/94

• SC/DSP:RI *SC/SPLB:DSSA *C/SPLB:DSSA *AD/DSSA

WHRuland SKWest CEMcCRACKEN MJVirgil io

07/21/94 07/21/94 07/2Z19402/ 07/25/94

• C/OEAB:DORS *AC/OGCB:DORS

AEChaffee ElDoolittle

07/26/94 07/28/94 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 concurrence

• SPLB:DSSA *DRS:RI *OGCB: DORS *TECH ED

EAConnell RJPaolano PCWen JMain

07/21/94 07/21/94 07/21/94 07/21/94

• SC/DSP:RI *SC/SPLB:DSSA *C/SPLB:DSSA *AD/DSSA

WHRuland SKWest CEMcCRACKEN MJVirgilio

07/21/94 07/21/94 07/22/94 07/25/94

• C/OEAB:DORS *AC/OGCB:DORS D/DORS

AEChaffee ELDoolittle BKGrimes9fL

07/26/94 07/28/94 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 concurrence

• SPLB:DSSA *DRS:RI *OGCB:DORS *TECH ED

EAConnell RJPaolino PCWen JMain

07/21/94 07/21/94 07/21/94 07/21/94

• SC/DSP:RI *SC/SPLB:DSSA *C/SPLB:DSSA *AD/DSSA

WHRuland SKWest CEMcCRACKEN MJVirgilio

07/21/94 07/21/94 07/22/94 07/25/94

• C/OEAB:DORS AC RS D/DORS

AEChaffee E le BKGrimes

07/26/94 07/ /94

1,0-w

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. Si ubsequently, 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.

~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 *OGCB:DORS *TECH ED

EAConnell RJPaolino PCWen JMain

07/21/94 07/21/94 07/21/94

• SC/DSP:RI *SC/SPLB:DSSA " P DSA AD/DSSAOA '

WHRuland SKWest CEMcCRACKEN MJVirqilio

07/21/94 07/21/94 07/Ap94 s 07/$6/94 C lG ORS AC/OGCB:DORS D/DORS

A0a ffee ELDoolittle BKGrimes

07/A/94 07/ /94 07/ /94 OFFICIAL RECORD COPY 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 J. Paolino,RI

(610) 337-5285 Attachment:

List of Recently Issued NRC Information Notices

SPLB:DSSA DRS:RI OGCB:gQRS TECH ED

EAConnell RJPaol ino PCWen 1- JMain asp

07/Z/ /94 07 I/94 07,l1/94 07/21/94 SC/DSP: R C/SPLB:DSSA AD/DSSA

WHRul and SKWest CEMcCRACKEN MJVirgilio

-8 07/%1/94 07/t- /94 07/ /94 07/ /94 C/OEAB:DORS AC/OGCB:DORS D/DORS

AEChaffee ELDoolittle BKGrimes

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