Information Notice 2002-34, Failure of Safety-Related Circuit Breaker External Auxiliary Switches at Columbia Generating Station: Difference between revisions

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{{#Wiki_filter:UNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, DC 20555-0001November 25, 2002NRC INFORMATION NOTICE 2002-34:FAILURE OF SAFETY-RELATED CIRCUITBREAKER EXTERNAL AUXILIARY SWITCHES
{{#Wiki_filter:UNITED STATES


===AT COLUMBIA GENERATING STATION===
NUCLEAR REGULATORY COMMISSION
 
OFFICE OF NUCLEAR REACTOR REGULATION
 
WASHINGTON, DC 20555-0001 November 25, 2002 NRC INFORMATION NOTICE 2002-34:                  FAILURE OF SAFETY-RELATED CIRCUIT
 
BREAKER EXTERNAL AUXILIARY SWITCHES
 
AT COLUMBIA GENERATING STATION


==Addressees==
==Addressees==
Line 22: Line 30:


==Purpose==
==Purpose==
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to informaddressees of failures of circuit breaker external auxiliary switches because of inadequate
The U.S. Nuclear Regulatory Commission (NRC) is issuing this information notice to inform


maintenance of the associated switchgear. It is expected that recipients will review the
addressees of failures of circuit breaker external auxiliary switches because of inadequate
 
maintenance of the associated switchgear. It is expected that recipients will review the


information for applicability to their facilities and consider actions, as appropriate, to avoid
information for applicability to their facilities and consider actions, as appropriate, to avoid


similar problems. However, suggestions in this information notice are not NRC requirements;
similar problems. However, suggestions in this information notice are not NRC requirements;
therefore, no specific action or written response is required.
therefore, no specific action or written response is required.


==Description of Circumstances==
==Description of Circumstances==
On February 14, 2002, at the Columbia Generating Station, the licensee initiated a requiredplant shutdown because of a mechanical problem in an emergency diesel generator (EDG)
On February 14, 2002, at the Columbia Generating Station, the licensee initiated a required
 
plant shutdown because of a mechanical problem in an emergency diesel generator (EDG)
output circuit breaker. Although the breaker was capable of closing and connecting the EDG to
output circuit breaker. Although the breaker was capable of closing and connecting the EDG to


its safety bus, its cubicle-mounted auxiliary contacts, called mechanism-operated cell (MOC)
its safety bus, its cubicle-mounted auxiliary contacts, called mechanism-operated cell (MOC)
switches, failed to change state as designed. The licensee determined that the MOC switch
switches, failed to change state as designed. The licensee determined that the MOC switch


failures associated with this breaker and other breakers of this type resulted in failure of various
failures associated with this breaker and other breakers of this type resulted in failure of various
Line 42: Line 54:
electrical distribution system control functions, including some non-safety loads not being
electrical distribution system control functions, including some non-safety loads not being


removed from the EDG bus following an accident signal.On June 29, 2001, during a refueling outage at the same plant, after breaker replacement, astandby service water pump breaker MOC switch failed to reposition during breaker closure.
removed from the EDG bus following an accident signal.


This failure recurred on November 19, 2001. A MOC switch contact prevented the pump
On June 29, 2001, during a refueling outage at the same plant, after breaker replacement, a
 
standby service water pump breaker MOC switch failed to reposition during breaker closure.
 
This failure recurred on November 19, 2001. A MOC switch contact prevented the pump


discharge valve from opening after a pump start, rendering the service water system and
discharge valve from opening after a pump start, rendering the service water system and
Line 50: Line 66:
supported systems, such as EDGs, inoperable.
supported systems, such as EDGs, inoperable.


DiscussionThe licensee believes the failure was caused by excessive resistance in the linkage betweenthe breaker and the MOC switches.  The licensee had not performed periodic maintenance on
Discussion


this linkage in the breaker cell housing.  Over time, dirt and dust accumulated and grease
The licensee believes the failure was caused by excessive resistance in the linkage between


hardened to increase the resistance in the linkage mechanism.   During the preceding refueling outage, ending in July 2001, the licensee replaced 22 safety-related 4160-volt circuit breakers, exchanging older design Westinghouse Type DHP-350 (air- magnetic) breakers with newer design, Westinghouse-dedicated, Cutler Hammer Type
the breaker and the MOC switches. The licensee had not performed periodic maintenance on


DHP-VR (vacuum replacement) breakers using Sure-Close
this linkage in the breaker cell housing. Over time, dirt and dust accumulated and grease


TM mechanisms to operate the MOCswitches. In the DHP-VR, the Sure-Close
hardened to increase the resistance in the linkage mechanism.


TM mechanism operates the MOC switches independently of thebreaker's main contacts so that the MOC switches can be operated at a slower speed to avoid
During the preceding refueling outage, ending in July 2001, the licensee replaced 22 safety- related 4160-volt circuit breakers, exchanging older design Westinghouse Type DHP-350 (air- magnetic) breakers with newer design, Westinghouse-dedicated, Cutler Hammer Type


excessive kinetic energy and wear.  In addition, the external MOC switch linkage drag won't
DHP-VR (vacuum replacement) breakers using Sure-CloseTM mechanisms to operate the MOC


stall the main contacts, even if the linkage is poorly maintained. However, because the design
switches.


of the Sure-Close
In the DHP-VR, the Sure-CloseTM mechanism operates the MOC switches independently of the


TM mechanism intentionally limits the force on the linkage, it does not havesufficient force margin to overcome the excessive drag of poorly maintained MOC switch
breakers main contacts so that the MOC switches can be operated at a slower speed to avoid


linkages (for an explanation of Sure-Close
excessive kinetic energy and wear. In addition, the external MOC switch linkage drag wont


TM operation, see "DHP -VR SURE CLOSEMechanism:  A Kinematic System Solution for Medium Voltage Circuit Breaker MOC Auxiliaries
stall the main contacts, even if the linkage is poorly maintained. However, because the design


Operation," U. S. Patent 5,856,643, Ronald E. Vaill, available from Cutler-Hammer Nuclear
of the Sure-CloseTM mechanism intentionally limits the force on the linkage, it does not have


Programs).The Columbia Generating Station experience illustrates that the newer design breakers with theSure-Close
sufficient force margin to overcome the excessive drag of poorly maintained MOC switch


TM mechanisms operating the MOC switches depend more heavily on the state ofmaintenance of the linkage than do the older design breakers coupled directly to the MOC
linkages (for an explanation of Sure-CloseTM operation, see DHP -VR SURE CLOSE


switches.  Older design breakers will eventually cause damage to poorly maintained MOC
Mechanism: A Kinematic System Solution for Medium Voltage Circuit Breaker MOC Auxiliaries


switches and linkages. In severe cases, poorly maintained MOC switches and linkages could
Operation, U. S. Patent 5,856,643, Ronald E. Vaill, available from Cutler-Hammer Nuclear


stall the older design breaker main contacts with potentially serious results.This information notice requires no specific action or written response.  If you have anyquestions about the information in this notice, please contact one of the technical contacts
Programs).


listed below or the appropriate project manager from the NRC's Office of Nuclear Reactor
The Columbia Generating Station experience illustrates that the newer design breakers with the


Regulation (NRR). /RA/William D. Beckner, Program Director
Sure-CloseTM mechanisms operating the MOC switches depend more heavily on the state of
 
maintenance of the linkage than do the older design breakers coupled directly to the MOC
 
switches. Older design breakers will eventually cause damage to poorly maintained MOC
 
switches and linkages. In severe cases, poorly maintained MOC switches and linkages could
 
stall the older design breaker main contacts with potentially serious results.
 
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 project manager from the NRCs Office of Nuclear Reactor
 
Regulation (NRR).
 
/RA/
                                              William D. Beckner, Program Director
 
Operating Reactor Improvements Program


===Operating Reactor Improvements Program===
Division of Regulatory Improvement Programs
Division of Regulatory Improvement Programs


Office of Nuclear Reactor RegulationTechnical contacts:V. Hodge, NRRSteven Alexander, NRR301-415-1861301-415-2995 E-mail: cvh@nrc.govE-mail: sda@nrc.govAttachment: List of Recently Issued NRC Information Notices
Office of Nuclear Reactor Regulation
 
Technical contacts: V. Hodge, NRR                      Steven Alexander, NRR
 
301-415-1861                    301-415-2995 E-mail: cvh@nrc.gov            E-mail: sda@nrc.gov
 
Attachment: List of Recently Issued NRC Information Notices
 
ML023300015 DOCUMENT NAME: G:\RORP\OES\STAFF FOLDERS\Hodge\event reviews\col_brkr\21016 short col_brkr inf.wpd
 
OFFICE OES:RORP:DRIP Tech Editor                    IQMB:DIPM        EEIB:DE
 
NAME      CVHodge              PKleene*            SDAlexander*    ASGill
 
DATE      11/07/2002          05/072002            11/07/2002      11/19/2002 OFFICE    C:EEIB:DE            SC:RORP:DRIP PD:RORP:DRIP


ML023300015 DOCUMENT NAME: G:\RORP\OES\STAFF FOLDERS\Hodge\event reviews\col_brkr\21016 short col_brkr inf.wpdOFFICEOES:RORP:DRIPTech EditorIQMB:DIPMEEIB:DENAMECVHodgePKleene*SDAlexander*ASGillDATE11/07/200205/07200211/07/200211/19/2002OFFICEC:EEIB:DESC:RORP:DRIPPD:RORP:DRIPNAMEJACalvoTReisWDBecknerDATE11/20/200211/22/200211/25/2002
NAME       JACalvo              TReis                WDBeckner
______________________________________________________________________________________OL = Operating License


CP = Construction PermitAttachment 1 LIST OF RECENTLY ISSUEDNRC INFORMATION NOTICES
DATE      11/20/2002          11/22/2002          11/25/2002


_____________________________________________________________________________________InformationDate of
Attachment 1 LIST OF RECENTLY ISSUED


===Notice No.        SubjectIssuanceIssued to===
NRC INFORMATION NOTICES
_____________________________________________________________________________________2002-33Notification of PermanentInjunction Against Neutron


===Products Incorporated of===
_____________________________________________________________________________________
Dickerson, Maryland11/21/2002All teletherapy and radiationprocessing licensees. 2002-29(Errata)Recent Design Problems in Safety Functions of Pneumatic
Information                                              Date of


Systems11/06/2002All holders of operating licensesor construction permits for
Notice No.              Subject                          Issuance        Issued to


nuclear power reactors.2002-32Electromigration onSemiconductor Integrated
_____________________________________________________________________________________
2002-33          Notification of Permanent            11/21/2002      All teletherapy and radiation


Circuits10/31/2002All holders of operating licensesfor nuclear power reactors except
Injunction Against Neutron                            processing licensees.


those who have ceased
Products Incorporated of
 
Dickerson, Maryland
 
2002-29          Recent Design Problems in            11/06/2002      All holders of operating licenses
 
(Errata)          Safety Functions of Pneumatic                          or construction permits for
 
Systems                                                nuclear power reactors.
 
2002-32          Electromigration on                  10/31/2002      All holders of operating licenses
 
Semiconductor Integrated                              for nuclear power reactors except
 
Circuits                                              those who have ceased


operations and have certified that
operations and have certified that
Line 120: Line 183:
fuel has been permanently
fuel has been permanently


removed from the reactor vessel.2002-31Potentially Defective UF
removed from the reactor vessel.


6Cylinder Valves (1-inch)10/31/2002All licensees authorized topossess and use source material
2002-31          Potentially Defective UF6            10/31/2002      All licensees authorized to
 
Cylinder Valves (1-inch)                              possess and use source material


and/or special nuclear material for
and/or special nuclear material for
Line 130: Line 195:
shipping of uranium hexafluoride
shipping of uranium hexafluoride


(UF 6) in 30- and 48-inchcylinders.2002-30Control and Surveillance ofPortable Gauges During Field
(UF6) in 30- and 48-inch
 
cylinders.
 
2002-30          Control and Surveillance of          10/30/2002      All NRC licensees authorized to
 
Portable Gauges During Field                           possess, use, transport, and store
 
Operations                                            portable gauges.
 
2002-29          Recent Design Problems in            10/15/2002      All holders of operating licenses
 
Safety Functions of Pneumatic                          or construction permits for
 
Systems                                                nuclear power reactors.
 
2002-28          Appointment of Radiation              09/27/2002      All medical licensees.
 
Safety Officers and Authorized


Operations10/30/2002All NRC licensees authorized topossess, use, transport, and store
Users Under 10 CFR Part 35 Note:            NRC generic communications may be received in electronic format shortly after they are


portable gauges.2002-29Recent Design Problems inSafety Functions of Pneumatic
issued by subscribing to the NRC listserver as follows:
                To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following


Systems10/15/2002All holders of operating licensesor construction permits for
command in the message portion:
                                    subscribe gc-nrr firstname lastname


nuclear power reactors.2002-28Appointment of RadiationSafety Officers and Authorized
______________________________________________________________________________________
OL = Operating License


Users Under 10 CFR Part 3509/27/2002All medical licensees.Note:NRC generic communications may be received in electronic format shortly after they areissued by subscribing to the NRC listserver as follows:To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the followingcommand in the message portion:subscribe gc-nrr firstname lastname}}
CP = Construction Permit}}


{{Information notice-Nav}}
{{Information notice-Nav}}

Latest revision as of 04:05, 24 November 2019

Failure of Safety-Related Circuit Breaker External Auxiliary Switches at Columbia Generating Station
ML023300015
Person / Time
Site: Columbia Energy Northwest icon.png
Issue date: 11/25/2002
From: Beckner W
NRC/NRR/DRIP/RORP
To:
Hodge, CV, NRR/DRIP/RORP, (415-1861)
References
IN-02-034
Download: ML023300015 (7)
v • d • e


UNITED STATES

NUCLEAR REGULATORY COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, DC 20555-0001 November 25, 2002 NRC INFORMATION NOTICE 2002-34: FAILURE OF SAFETY-RELATED CIRCUIT

BREAKER EXTERNAL AUXILIARY SWITCHES

AT COLUMBIA GENERATING STATION

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 inform

addressees of failures of circuit breaker external auxiliary switches because of inadequate

maintenance of the associated switchgear. 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 in this information notice are not NRC requirements;

therefore, no specific action or written response is required.

Description of Circumstances

On February 14, 2002, at the Columbia Generating Station, the licensee initiated a required

plant shutdown because of a mechanical problem in an emergency diesel generator (EDG)

output circuit breaker. Although the breaker was capable of closing and connecting the EDG to

its safety bus, its cubicle-mounted auxiliary contacts, called mechanism-operated cell (MOC)

switches, failed to change state as designed. The licensee determined that the MOC switch

failures associated with this breaker and other breakers of this type resulted in failure of various

electrical distribution system control functions, including some non-safety loads not being

removed from the EDG bus following an accident signal.

On June 29, 2001, during a refueling outage at the same plant, after breaker replacement, a

standby service water pump breaker MOC switch failed to reposition during breaker closure.

This failure recurred on November 19, 2001. A MOC switch contact prevented the pump

discharge valve from opening after a pump start, rendering the service water system and

supported systems, such as EDGs, inoperable.

Discussion

The licensee believes the failure was caused by excessive resistance in the linkage between

the breaker and the MOC switches. The licensee had not performed periodic maintenance on

this linkage in the breaker cell housing. Over time, dirt and dust accumulated and grease

hardened to increase the resistance in the linkage mechanism.

During the preceding refueling outage, ending in July 2001, the licensee replaced 22 safety- related 4160-volt circuit breakers, exchanging older design Westinghouse Type DHP-350 (air- magnetic) breakers with newer design, Westinghouse-dedicated, Cutler Hammer Type

DHP-VR (vacuum replacement) breakers using Sure-CloseTM mechanisms to operate the MOC

switches.

In the DHP-VR, the Sure-CloseTM mechanism operates the MOC switches independently of the

breakers main contacts so that the MOC switches can be operated at a slower speed to avoid

excessive kinetic energy and wear. In addition, the external MOC switch linkage drag wont

stall the main contacts, even if the linkage is poorly maintained. However, because the design

of the Sure-CloseTM mechanism intentionally limits the force on the linkage, it does not have

sufficient force margin to overcome the excessive drag of poorly maintained MOC switch

linkages (for an explanation of Sure-CloseTM operation, see DHP -VR SURE CLOSE

Mechanism: A Kinematic System Solution for Medium Voltage Circuit Breaker MOC Auxiliaries

Operation, U. S. Patent 5,856,643, Ronald E. Vaill, available from Cutler-Hammer Nuclear

Programs).

The Columbia Generating Station experience illustrates that the newer design breakers with the

Sure-CloseTM mechanisms operating the MOC switches depend more heavily on the state of

maintenance of the linkage than do the older design breakers coupled directly to the MOC

switches. Older design breakers will eventually cause damage to poorly maintained MOC

switches and linkages. In severe cases, poorly maintained MOC switches and linkages could

stall the older design breaker main contacts with potentially serious results.

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 project manager from the NRCs Office of Nuclear Reactor

Regulation (NRR).

/RA/

William D. Beckner, Program Director

Operating Reactor Improvements Program

Division of Regulatory Improvement Programs

Office of Nuclear Reactor Regulation

Technical contacts: V. Hodge, NRR Steven Alexander, NRR

301-415-1861 301-415-2995 E-mail: cvh@nrc.gov E-mail: sda@nrc.gov

Attachment: List of Recently Issued NRC Information Notices

ML023300015 DOCUMENT NAME: G:\RORP\OES\STAFF FOLDERS\Hodge\event reviews\col_brkr\21016 short col_brkr inf.wpd

OFFICE OES:RORP:DRIP Tech Editor IQMB:DIPM EEIB:DE

NAME CVHodge PKleene* SDAlexander* ASGill

DATE 11/07/2002 05/072002 11/07/2002 11/19/2002 OFFICE C:EEIB:DE SC:RORP:DRIP PD:RORP:DRIP

NAME JACalvo TReis WDBeckner

DATE 11/20/2002 11/22/2002 11/25/2002

Attachment 1 LIST OF RECENTLY ISSUED

NRC INFORMATION NOTICES

_____________________________________________________________________________________

Information Date of

Notice No. Subject Issuance Issued to

_____________________________________________________________________________________

2002-33 Notification of Permanent 11/21/2002 All teletherapy and radiation

Injunction Against Neutron processing licensees.

Products Incorporated of

Dickerson, Maryland

2002-29 Recent Design Problems in 11/06/2002 All holders of operating licenses

(Errata) Safety Functions of Pneumatic or construction permits for

Systems nuclear power reactors.

2002-32 Electromigration on 10/31/2002 All holders of operating licenses

Semiconductor Integrated for nuclear power reactors except

Circuits those who have ceased

operations and have certified that

fuel has been permanently

removed from the reactor vessel.

2002-31 Potentially Defective UF6 10/31/2002 All licensees authorized to

Cylinder Valves (1-inch) possess and use source material

and/or special nuclear material for

the heating, emptying, filling, or

shipping of uranium hexafluoride

(UF6) in 30- and 48-inch

cylinders.

2002-30 Control and Surveillance of 10/30/2002 All NRC licensees authorized to

Portable Gauges During Field possess, use, transport, and store

Operations portable gauges.

2002-29 Recent Design Problems in 10/15/2002 All holders of operating licenses

Safety Functions of Pneumatic or construction permits for

Systems nuclear power reactors.

2002-28 Appointment of Radiation 09/27/2002 All medical licensees.

Safety Officers and Authorized

Users Under 10 CFR Part 35 Note: NRC generic communications may be received in electronic format shortly after they are

issued by subscribing to the NRC listserver as follows:

To subscribe send an e-mail to <listproc@nrc.gov >, no subject, and the following

command in the message portion:

subscribe gc-nrr firstname lastname

______________________________________________________________________________________

OL = Operating License

CP = Construction Permit


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