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
From:	Grimes B K Office of Nuclear Reactor Regulation
To:
References
IN-96-024, NUDOCS 9604220229
Download: ML031060110 (14)

UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555-0001 April 25, 1996 NRC INFORMATION

NOTICE 96-24: PRECONDITIONING

OF MOLDED-CASE

CIRCUIT BREAKERS BEFORE SURVEILLANCE

TESTING

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 alert addressees

to the detrimental

effect that preconditioning

of molded-case

circuit breakers could have on the diagnostic

validity of surveillance

tests. It is expected that recipients

will review this information

for applicability

to their facilities

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

However, suggestions

contained

in this information

notice are not NRC requirements;

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

of Circumstances

During an inspection

at the Diablo Canyon Nuclear Power Plant (IR 50-275, 323/94-27 dated December 21, 1994), NRC inspectors

noted that the licensee preconditioned

circuit breakers before performing

surveillance

testing.Before the overcurrent

trip testing, Diablo Canyon staff exercised

the circuit breakers by manually opening and closing them three times. The plant staff'did not record the as-found condition

of the breakers in terms of unexercised

trip currents and times.During another inspection

at the South Texas Project (IR 50-498, 499/94-35 dated January 19, 1995), NRC inspectors

noted that the licensee exercised similar circuit breakers manually at least five times before testing the overcurrent

trip unit.Discussion

A molded-case

circuit breaker is one of the most widely used protective

devices for electrical

circuits at nuclear power plants. Its proper operation is essential

for the protection

and safe operation

of plant electrical

equipment.

Many circuit breakers are continuously

energized

for long periods.Often they are in service for years and are rarely, if ever, called upon to perform a protective

function.

Nevertheless, when needed, they must rapidly isolate a faulted or overloaded

circuit to prevent equipment

damage.Therefore, for the safe operation

of the electrical

distribution

system equipment

of a nuclear power plant, it is important

to periodically

verify their continued

reliability..K VE uor~cEya-0OZ

%6qZ 'I

K>I IN 96-24 April 25, 1996 Periodic inspection

and testing of circuit breakers in their as-found condition

is an appropriate

way of demonstrating

the functional

operability

of the breaker and of detecting

any degradation.

However, the practice of preconditioning

before testing (e.g., lubricating

pivot points and manually cycling the breaker) defeats the purpose of the periodic test. Such preconditioning

does not confirm continued

operability

between tests nor does it provide information

on the condition

of the circuit breaker for trending purposes.

Testing some circuit breakers in the as-found condition

can provide useful data on which to base decisions

on surveillance

intervals

and the ability of the untested circuit breakers to perform their intended function.Since only a fraction of the circuit breakers are tested each refueling

outage to justify the operability

of the remaining

circuit breakers, preconditioning

before testing does not provide the expected assurance

of the operability

of remaining

breakers which are not tested. By preconditioning

circuit breakers, useful information

may be lost because the breaker may not have been capable of performing

its intended function without preconditioning.

To correct this situation, Diablo Canyon Power Plant plans to revise the electrical

maintenance

procedure

before the next surveillance

test has to be performed.

The revised procedures

will state that electrical

testing should be performed

before any intentional

manual exercising

of the breakers, and to ensure that electrical

testing on breakers with removable

trip units is performed

before removing the trip unit.Some plants have older technical

specification

bases that cite National Electrical

Manufacturers

Association (NEMA) Standard AB 2-1980. This version of the standard specifies

mechanical

cycling of circuit breakers prior to electrical

testing. In later versions of this standard, this procedure

was deleted. There appears to be no valid technical

need for mechanical

cycling prior to electrical

surveillance

testing.The NRC has issued other generic communications

on molded-case

circuit breaker applications

and testing: NRC Information

Notice (IN) 92-51, and its Supplement

1, "Misapplication

and Inadequate

Testing of Molded-Case

Circuit Breakers;" IN 93-26, "Grease Solidification

Causes Molded Case Circuit Breaker Failure to Close;" and IN 93-64, "Periodic

Testing and Preventive

Maintenance

of Molded-Case

Circuit Breakers."

If I IN 96-24 April 25, 1996 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. /a L.." Brian K. Grimes, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Sikhindra

Mitra, NRR (301) 415-2783 Internet:skml@nrc.gov

Steve Alexander, NRR (301) 415-2995 Internet:sda@nrc.gov

Christopher

Myers, RIV (817) 860-8144 Internet:cjm@nrc.gov

Attachment:

List of Recently Issued NRC Information

Notices-tw@ / "Y

K Attachment

IN 96-24 April 25, 1996 LIST OF RECENTLY ISSUED NRC INFORMATION

NOTICES Information

Date of Notice No. Subject Issuance Issued to 96-23 96-22 96-21 96-20 Fires in Emergency

Diesel Generator

Exciters During Operation

Following

Unde-tected Fuse Blowing Improper Equipment

Set-tings Due to the Use of Nontemperature-Compensated

Test Equipment Safety Concerns Related to the Design of the Door Interlock

Circuit on Nucletron

High-Dose

Rate and Pulsed Dose Rate Remote Afterloading

Brachytherapy

Devices Demonstration

of Associ-ated Equipment

Compliance

with 10 CFR 34.20 Failure of Tone Alert Radios to Activate When Receiving

a Shortened Activation

Signal Compliance

with 10 CFR Part 20 for Airborne Thorium Loss of Reactor Coolant Inventory

and Potential Loss of Emergency

Mitiga-tion Functions

While in a Shutdown Condition 04/22/96 04/11/96 04/10/96 04/04/96 04/02/96 03/25/96 03/25/96 All holders of OLs or CPs for nuclear power reactors All holders of OLs or CPs for nuclear power reactors All U.S. NRC Medical to the Licensees

authorized

to use brachytherapy

sources in high- and pulsed-dose-rate

remote afterloaders

All industrial

radiography

licensees

and radiography

equipment

manufacturers

All holders of OLs or CPs for nuclear power reactors All material licensees authorized

to possess and use thorium in unsealed form All holders of OLs or CPs for PWR power plants 96-19 96-18 95-03 Supp. 1 OL = Operating

License CP -Construction

Permit

K2 2 IN 96-24 April 25, 1996 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, Acting Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Sikhindra

Mitra, NRR (301) 415-2783 Internet:skml@nrc.gov

Steve Alexander, NRR (301) 415-2995 Internet:sda@nrc.gov

Christopher

Myers, RIV (817) 860-8144 Internet:cjm@nrc.gov

Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 96-24.IN Tech Editor reviewed 9/21/95 To receive a copy of this document, Indicate In the box: 'C' -Copy without enclosures

'E" = Copy with sncloRre l -= No copy OFFICE Contacts C IEELB NAME CMyers

• JCalvo

• AChatfee s SMitra * /SAlexander*

7 , DATE 4/22/96 4/15/96 4/22/96 4/LT/96 OFFICIAL RECORD COPY

IN 96-XX April XX, 1996 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.Dennis M. Crutchfield, Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Sikhindra

Mitra, NRR (301) 415-2783 Internet:

skmlnrc.gov

Christopher

Myers, RIV (817) 860-8144 Internet:

cjm@nrc.gov

Steve Alexander, NRR (301) 415-2995 Internet:

sda@nrc.gov

Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN To receive a copy of this document.

Indicate In the box: Tech Editor reviewed 9/21/95'C' -Copy without enclosures

fEw -Copy wi th enclosures

'N' -No copy OFFICE IContacts

C/EELB I D/DRPI l NAME CMyers

• JCalvo

• AChaffee DCrutchfield

SMitra *SAlexanderLnfi_

DATE 4 /15/96 7' 4/15/96 4/ /96 4/ /96.-------UICLIAL KECOKR COPY ,44 I 1 i< -' IN 96-XX April XX, 1996 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.Dennis M. Crutchfield, Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Sikhindra

Mitra, NRR (301) 415-2783 Internet:

skmlnrc.gov

Christopher

Myers, RIV (817) 860-8144 Internet:

cjm~nrc.gov

Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN Tech Editor reviewed 9/21/95 To 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 I NAME CMyers

• JCalvo

• AChaffee DCrutchfield

SMitra *DATE 4 /I5/96 4/11 /96 4/ 4/ /96 OFFICIAL RECORD COPY

IN 96-XX April XX, 1996 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.Dennis M. Crutchfield, Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Christopher

Myers, RIV (817) 860-8144 Sikhindra

Mitra, NRR (301) 415-2783 Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN Tech Editor reviewed 9/21/95 To receive a copy of this document.

Indicate In the box: wCw = Copy without enclosures

'E" -Copy with enclosures

'N'= No copy OFFICE Contacts C/EELB I NAME Myers JCalvoJy r AChaffee DCrutchfield

I ~SMi tra_ _ _ _ _ _ _DATE 4 /16796 4/ I7 /96 4/ /96 4/ /96 OFFICIAL RECORD COPY

IN 96-XX April xx, 1996 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.Dennis M. Crutchfield, Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Tom Westerman, RIV (817) 860-8145 Christopher

Myers, RIV (817) 860-8144 Stephen Alexander, NRR (301) 415-2995 Sikhindra

Mitra, NRR (301) 415-2783 Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN T - 5 .LL.1. .I *k. i hn,.. tC = -Cnnu without enclosures

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DATE I1 / g/95 t /, /95 / /95 01/25/95 / /95 OFFICE TECH ED N SC:SIB:DISP

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AChaffee DMCrutchfield

DATE IJ /f/96 10/04/95 I /95 /95 /95 OFFICIAL RECORD COPY

IN 96-XX January xx, 1995 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.Dennis M. Crutchfield, Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Tom Westerman, RIV (817) 860-8145 Christopher

Myers, RIV (817) 860-8144 Stephen Alexander, NRR (301) 415-2995 Sikhindra

Mitra, (301) 415-2783 NRR Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN To 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 BDS NAME TWesterman

CMyers _ _ _ TP Gwyn* SAl exander DATE / /95 1 I / /9 IL/5 01_/25/95

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eld DATE I /oF/9 _ 10/04/95 / /95 / /95 / /95 OFFICIAL RECORD COPY

IK 'I IN 95-XX September

xx, 1995 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.Dennis M. Crutchfield, Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

contacts: Tom Westerman, RIV (817) 860-8145 Christopher

Myers, (817) 860-8144 RIV Stephen Alexander, NRR (301) 415-2995 Sikhindra

Mitra, NRR (301) 415-2783 Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN Te raclva a etonw of thb document Indicate hI Om box: 'C' -Copv without enclosures

• See previous concurrence

'E -Copy with enclosures

'N- -No copy OFFICE R E RIV E R RIV E PSIB:DISP

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c CMyers / T/5 6_ _ _w n SAlexander

DATE I /Teean/95 jC/1y/95 / /95 _ T/ZS/95 I /95 OFFICE TECH ED N SC:SIB:DISP

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ID:DRPM NAME TKoshy EFGoodwin

RJK AChaffee DMCrutchfield

DATE 9/26/95 y 95 V // /95 / /95 OFFICIAL RECORD COPY

IN 95-XX September

xx, 1995 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, Deputy Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

Contacts:

Tom Westerman, RIV (817) 860-8145 Christopher

Myers, RIV (817) 860-8144 Stephen Alexander, NRR (301) 415-2995 Sikhindra

Mitra, NRR (301) 415-2783 Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN * , See previous concurrence

To receive a copy of this document.

Indicate In the box: 'C' Copy without enclosures

E' -Copy with enclosures

N -No copy OFFICE RIY I E RIY E RIYE RIV E PSIB:DISP

E NAME TWesterman

CMyers ____ _ SAlexander

DATE / /LE95 / /95 I /95 /95 / /95 OFFICE TECH ED I N SC:SIB:DISP

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l DD:DRPM NAME AChaffee BKGrimes DATE I /95 / /95 l//95 OFFICIAL RECORD COPY

IN 95-XX August XX, 1995 one of the technical

contacts listed below or the appropriate

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

Office of Nuclear Reactor Regulation

Technical

Contacts: Tom Westerman, RIV (817) 860-8145 Christopher

Myers, RIV (817) 860-8144 Stephen Alexander, NRR (301) 415-2995 Sikhindra

Mitra, NRR (301) 415-2783 Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN a nv Cf thids donument.

indicate In the box:* .See previous concurrence

'C' -Coov without enclosures

'E' -Copy with enclosures

'N' .No copy To rAceivA OFFICE RIV l1 El t E RE R E RIV I E lPSIB:DISP

I E NAME TWesterman

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DATE / /95 I /95 / /95 /95 /95 OFFICE TECH ED N SC:SIB:DISP

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DD:DRPM NAME AChaffee BKGrimes DATE I /95 / /95 / /95 OFFICIAL RECORD COPY

K-/IN 95-XX August XX, 1995 one of the technical

contacts listed below or the Nuclear Reactor Regulation (NRR) project manager.appropriate

Office of Brian K. Grimes, Deputy Director Division of Reactor Program Management

Office of Nuclear Reactor Regulation

Technical

Contacts: Tom Westerman, RIV (817) 860-8145 Christopher

Myers, RIV (817) 860-8144 Stephen Alexander, NRR (301). 415-2995 Sikhindra

Mitra, NRR (301) 415-2783 Attachment:

List of Recently Issued NRC Information

Notices DOCUMENT NAME: 95-XX.IN To receive a copy of this document.

Indicate In the box:* = See previous concurrence

wEd -Copy with oncosurss

rW -No copy NCR -Copy without endosurms OFFICE RIV I E RIY E RIV E RIV I E PSIB:DISP

I E NAME TWesterman

CMyers I jSAlexander

DATE / /95 / /95 1/. /95 /95 / /95 OFFICE TECH ED N SC:SIB:DISP

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