Information Notice 1993-26, Grease Soldification Causes Molded-Case Circuit Breaker Failure to Close

Grease Soldification Causes Molded-Case Circuit Breaker Failure to Close

ML031080033
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, 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, Crane
Issue date:	01/31/1994
From:	Grimes B Office of Nuclear Reactor Regulation
To:
References
IN-93-026, Suppl 1, NUDOCS 9401250302
Download: ML031080033 (8)

UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 January 31, 1994 NR2' INFORMATION NOTICE 93-26, SUPPLEMENT 1: GREASE SOLIDIFICATION CAUSES

MOLDED-CASE CIRCUIT BREAKER

FAILURE TO CLOSE

Addressees

All holders of operating licenses or construction permits for nuclear power

reactors.

Purpose

The U.S. Nuclear Regulatory Commission (NRC) is Issuing this information

notice to supplement information regarding a problem with a 400-amp frame,

600-V ac molded-case circuit breaker manufactured by General Electric

Corporation (GE) (Part No. TJK436Y400) which failed to close when required due

to grease solidification. 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.

Description of Circumstances

On March 26, 1992, an engineered safety feature (ESF) actuated at the

Nine Mile Point Nuclear Station Unit 2 (NMP2) because of the loss of output

power from an uninterruptible power supply (UPS) while the loads were being

transferred from UPS power to the maintenance supply power. During the

transfer, the maintenance supply output circuit breaker (CB-4) failed to

close, causing a loss of power to the standby gas treatment system radiation

monitoring cabinet, a false-high radiation signal, a group 9 (primary

containment purge system) primary containment isolation, the loss of a control

room fire panel annunciator, and a loss of communication between the radiation

monitoring system computer and non-Class IE radiation monitors. The operator

immediately took corrective action to close circuit breaker CB-4 manually to

restore the UPS loads. The UPS loads lost power for approximately 12 minutes

during the event.

After Information Notice (IN)93-26 was issued on April 7, 1993, additional

information was obtained from GE and NMP2. The additional information in

this supplement is intended to assist recipients in determining the

significance of this potential failure mode at their facilities.

- s 0900&S

9401250302i_ :i4 (O3i

1. RETURN TO REGULATGRY03017?

CENTRAL FILES

ROO&U

KI< 93-26, Supp. I

January 31, 1994 Discussion

Niagara Mohawk Power Corporation, the licensee for Nine Mile Point 2 (LER 92-007-00), and Wyle Laboratories (Report No. 42370-RCCB-I) determined

that circuit breaker CB-4 had failed to close because the grease used at the

pivot points inside the breaker had dried out and solidified. When the grease

dried out, the metal-to-metal contact areas experienced increased friction and

eventual gouging. The friction caused the breaker to become increasingly more

difficult to close, until, finally, the breaker would not close at all. The

licensee located all breakers of the same make, model, and year as the one

that failed and scheduled their replacement.

Certain observations were made in the NMP2 analysis relative to these

breakers:

1. The safety function of these breakers is both to open and close

automatically. Normally, the only electrical safety function of a

breaker is its ability to trip. None of the breakers of this type at

Nine Mile Point 2 have failed to trip when required.

2. Due to the nature of the application of these molded-case switches, they

were cycled extensively (approximately 200-400 times). This is more than

a normal molded-case circuit breaker used in a distribution panel.

3. The breakers were in close proximity to the UPS transformers causing

operation above normal ambient conditions, which may or may not have

contributed to the solidification of the grease.

GE has stated that in early 1980 the soap-based and clay-based grease used in

this style molded-case circuit breakers was replaced with a synthetic

lubricant as a product enhancement. However, older molded-case circuit

breakers using the clay-based and soap-based grease may still be in use at

other plants, in similar applications.

- V zi 93-26, Supp. 1 January 31, 1994 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact listed below or the appropriate Office of Nuclear

Reactor Regulation (NRR) project manager.

nan K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: Mark D. Pratt, NRR

(301) 504-2701 Attachment:

List of Recently Issued NRC Information Notices

• ~'~IN 93-26, Supp. 1 January 31, 1994 response. If

This information notice requires no specific action or writtenplease contact

you have any questions about the information in this notice, of Nuclear

the technical contact listed below or the appropriate Office

Reactor Regulation (NRR) project manager.

Odginal fgned by

Brian K.Grimes

Brian K. Grimes, Director

Division of Operating Reactor Support

Office of Nuclear Reactor Regulation

Technical contact: Mark D. Pratt, NRR

(301) 504-2701 Attachment:

List of Recently Issued NRC Information Notices

EELB Concurrence obtained by M.D. Pratt

• EELB:DE:NRR SC/EELB:DE:NRR C/EELB:DE:NRR *OGCB:DORS:NRR *RPB:ADM

EWWeiss* CHBerlinger* /~NECampbell Tech Ed

MDPratt 12/22/93

12/22/93 12/17/93

• D/DE *C/OGCB:DORS:NRR /D RR

WHodges GHMarcus

01/12/94 12/22/93 "01k (/94 DOCUMENT NAME: 93-26SP1.IN

r-

IN 93-26, Supp. 1 January 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

the technical contact 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 contact: Mark D. Pratt, NRR

(301) 504-2701 Attachment:

List of Recently Issued NRC Information Notices

EELB Concurrence obtained by M.D. Pratt

• EELB:DE:NRR SC/EELB:DE:NRR C/EELB:DE:NRR *OGCB:DORS:NRR *RPB: ADM

MDPratt EWWeiss CHBerlinger NECampbell Tech Ed

12/22/93 / / 12/17/93 12/22/93 D/DE , *C/OGCB:DORS:NRR D/DORS:NRR

WHodge'V'W GHMarcus BKGrime'l

01/12./94 12/22/93 01/ /94X

DOCUMENT NAME: MCCBSUPP.NEC

I

IN 93-XX

December xx, 1993 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact 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 contact: Mark D. Pratt, NRR

(301) 504-2701 Attachment:

List of Recently Issued NRC Information Notices

(FEELB Concurrence obtained by M.D. Pratt ./A /Ie/w/Z3 EELB:DE:NRR SC/EELB:DE:NRR C/EELB:DE:NRR OGCB:DORS:NRR RPB:ADM V

4 MDPrat H&y EWWeiss #) CHBerl ingerg' NECampbell Tech Ed

l l 12/rP/93 3' (;/ lvq3 D/DORS:NRR C/OGCB:DORS:NRR

BKGrimes GHMarcusmf-I

12/ /93 12/2.2./93 DOCUMENT NAME: MCCBSUPP. NEC

IN 93-XX

December xx, 1993 This information notice requires no specific action or written response. If

you have any questions about the information in this notice, please contact

the technical contact 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 contact: Mark D. Pratt, NRR

(301) 504-2701 Attachment:

List of Recently Issued NRC Information Notices

GEELB Concurrence obtained by M.D. Pratt

EELB:DE:NRR SC/EELB:DE:NRR C/EELB:DE:NRR OGCB:DORS:NRR RPB:ADM

MDPratt& EWWeisst) CHBerlingeiO NECampbell TechEO

I1/ 12/17/93 4.C.

D/DORS:NRR C/OGCB: DORS:NRIR

BKGrimes GHMarcus

12/ /93 12/ /93 DOCUMENT NAME: MCCBSUPP.NEC

Attaci t

IN 93-26, Supp. 1 January 31, 1994 Page I of I

LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

Informati0n, -Date of

Notice No. Subject Issuance Issued to

94-07 Solubility Criteria for 01/28/94 All byproduct material and

Liquid Effluent Releases fuel cycle licensees with

to Sanitary Sewerage Under the exception of licensees

the Revised 10 CFR Part 20 authorized solely for

sealed sources.

Potential Failure of 01/28/94 All holders of OLs or CPs

Long-Term Emergency for boiling water reactors.

Nitrogen Supply for the

Automatic Depressurization

System Valves

93-85, Problems with X-Relays 01/20/94 All holders of OLs or CPs

Rev. 1 in DB- and DHP-Type for nuclear power reactors.

Circuit Breakers Manu- factured by Westinghouse

Potential Failure of 01/19/94 All holders of OLs or CPs

Steam Generator Tubes for pressurized water

with Kinetically Welded reactors (PWRs).

Sleeves

94-04 Digital Integrated 01/14/94 All NRC licensees except

Circuit Sockets with licensed operators.

Intermittent Contact

94-03 Deficiencies Identified 01/11/94 All holders of OLs or CPs

during Service Water System for nuclear power reactors.

Operational Performance

Inspections

94-02 Inoperability of General 01/07/94 All holders of OLs or CPs

Electric Magne-Blast for nuclear power reactors.

Breaker Because of Mis- alignment of Close-Latch

Spring

Turbine Blade Failures 01/07/94 All holders of OLs or CPs

Caused by Torsional for nuclear power reactors.

Excitation from Electrical

System Disturbance

OL e Operating License

CP = Construction Permit