Information Notice 1988-75, Disabling of Diesel Generator Output Circuit Breakers by Anti-Pump Circuitry: Difference between revisions

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{{#Wiki_filter:IUNITED STATESNUCLEAR REGULATORY COMMISSIONOFFICE OF NUCLEAR REACTOR REGULATIONWASHINGTON, D.C. 20555September 16, 1988NRC INFORMATION NOTICE NO. 88-75: DISABLING OF DIESEL GENERATOR OUTPUTCIRCUIT BREAKERS BY ANTI-PUMP CIRCUITRY
{{#Wiki_filter:I UNITED STATES NUCLEAR REGULATORY
 
COMMISSION
 
===OFFICE OF NUCLEAR REACTOR REGULATION===
WASHINGTON, D.C. 20555 September
 
16, 1988 NRC INFORMATION
 
NOTICE NO. 88-75: DISABLING
 
OF DIESEL GENERATOR
 
OUTPUT CIRCUIT BREAKERS BY ANTI-PUMP
 
CIRCUITRY


==Addressees==
==Addressees==
:All holders of operating licenses or construction permits for nuclear powerreactors.
:
All holders of operating
 
licenses or construction
 
permits for nuclear power reactors.


==Purpose==
==Purpose==
:This information notice is being provided to alert addressees to potentialproblems where the capability to either automatically or manually closediesel generator circuit breakers from the control room may be lost. Itis expected that recipients will review the information for applicabilityto their facilities and consider actions, as appropriate, to avoid similarproblems. However, suggestions contained in this information notice do notconstitute NRC requirements; therefore, no specific action or written responseis required.
: This information
 
notice is being provided to alert addressees
 
to potential problems where the capability
 
to either automatically
 
or manually close diesel generator
 
circuit breakers from the control room may be lost. 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 do not constitute
 
NRC requirements;  
therefore, no specific action or written response is required.Description
 
of Circumstances:
On June 5, 1988, operators
 
at Browns Ferry Unit 3 were unable to reclose the diesel generator
 
output breakers to the 4-kV shutdown boards from the control room during a loss-of-power/loss-of-coolant-accident (LOP/LOCA)
test. During the test, the output breakers connected
 
the diesel generators
 
to their respec-tive 4-kV shutdown boards after the LOP signal was generated;
however, the breakers tripped and remained open after receiving
 
the LOCA signal. Operators diagnosed
 
the output breaker lockout problem using system electrical
 
configu-ration drawings.
 
An operator was sent to the 4-kY shutdown board to manually transfer output breaker control power to its alternate
 
source. This momentarily
 
removed power, enabling the breaker to close when the power was restored.On October 14, 1987, an operator at Wolf Creek Generating
 
Station manually tripped the output circuit breaker of the emergency
 
diesel generator (EDG)from the control room. At the time, the EDG was supplying
 
a vital bus. When the operators
 
tried to reenergize
 
the vital bus from the still-operating
 
EDG, they found that they could not close the EDG output breaker from the control room. The vital bus was finally reenergized
 
from the offsite power supply.Through examination
 
of the breaker control schematics
 
the licensee later found that the EDG circuit breaker could be closed by cycling the EDG mode switch at the EDG local control station.880920197 IN 88-75 September
 
16, 1988 Discussion:
The anti-pump
 
circuit configuration
 
will protect large breakers from rapid cycling and, under certain circumstances, will prevent breaker closure. At Browns Ferry Unit 3, a unique sequence of events, a LOP signal followed within 6 seconds by a LOCA signal, led to the discovery
 
of a design deficiency
 
of this circuit configuration.
 
Contacts from the undervoltage
 
relay will seal in the breaker anti-pump
 
relay until the undervoltage
 
condition
 
on the 4-kV boards clears.The circuit is designed such that following
 
a LOP, the undervoltage
 
condition must exist for at least 5 seconds and the diesel. must reach rated speed before the diesel generator
 
output breaker will close on the bus. Once the breaker has closed, the closure spring recharge motor and the breaker anti-pump
 
relay will be energized.
 
A fully discharged
 
closure spring requires 2 seconds for the spring to be fully recharged.
 
During this 2 second window the anti-pump coil will remain energized
 
via contacts sensing spring position, and if an undervoltage
 
condition
 
exists on the 4-kY bus it will seal in and lock open the breaker.During the Browns Ferry event, the EDG output breaker closed 5 seconds after the LOP signal, the undervoltage
 
condition
 
was eliminated, and the undervoltage
 
relay began its 5 second cycle to reset from the undervoltage
 
condition.
 
About 1.5 seconds 1ater. the. LOCA-signaL-retr-ipped-the-breaker-and-created-another--
undervoltage
 
condition
 
on the 4-kV bus. At this point, because the undervoltage
 
relay had not completed
 
its reset cycle, the undervoltage
 
relay remained in its undervoltage
 
state. Therefore, the undervoltage
 
relay sealed in the still-energized
 
anti-pump
 
relay because the undervoltage
 
condition
 
occurred before the breaker charging spring was fully charged. Thus, the breaker could not be closed from the control room either manually or automatically
 
until control power was removed, which deenergized
 
the anti-pump
 
relay.The Browns Ferry licensee modified the breaker control logic to prevent the anti-pump relay from sealing in during a LOCA condition
 
by adding a time-delay
 
relay in the breaker trip coil circuitry.
 
This relay will be energized
 
by a LOCA signal and its contact in the anti-pump
 
coil seal-in path will open after a 2-to 5-second delay to prevent anti-pump
 
coil seal-in and breaker lockout.The Wolf Creek EDG output circuit breaker has automatic
 
closing logic to close the circuit breaker when the following
 
five permissives
 
are satisfied:
(1) Both offsite circuit breakers are open'(2 The EDG mode switch is in the automatic
 
mode.(3 Lockout relays are deenergized.
 
(4 A 3-second time delay has elapsed.(5) The EDG has reached operating
 
speed and voltage.This logic sends a constant close signal to the circuit breaker that keeps the breaker's
 
internal anti-pump
 
relay energized
 
as long as the logic permissives
 
are satisfied.
 
The anti-pump
 
relay prevents the circuit breaker from cycling if attempts are made to hold the breaker closed against a valid trip signal.I',
IN 88-75 September
 
16, 1988 When the Wolf Creek operator manually tripped the EDG output breaker, the auto-matic closing logic permissives
 
remained satisfied.
 
Therefore, the anti-pump relay remained energized, preventing
 
reclosure
 
of the circuit breaker. Cycling the EDG mode control switch at the local control station allowed the circuit breaker to reclose by momentarily
 
interrupting
 
the automatic
 
close signal, there-by resetting
 
the anti-pump
 
logic. When the mode switch contact was reclosed by returning
 
the switch to the "auto' position, the circuit breaker's
 
automatic closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in the control room to enable the operator to reclose the EDG circuit breaker from the control room. This switch was originally
 
intended only as a means of paralleling
 
the EDG with the offsite power supply. With the current modification, the switch can be used to reset the anti-pump
 
logic and allow the automatic
 
circuit to re-close the breaker. The modification
 
added a contact that is closed in the "normal" position and open in the "trip" and "pull to lock" positions
 
of the control switch.When operators
 
manually trip the EDG circuit breaker from this control switch, the contacts open to interrupt
 
the close circuit and reset the circuit breaker anti-pump
 
relay. If the operator wishes to keep the breaker open, he must put the switch in the "pull to lock" position.
 
Returning
 
the switch to the "normal" position completes
 
the automatic
 
close circuit and the breaker recloses.It should be noted that although the above discussion
 
has dealt only with EDG output- circuit breakers, anti-pump
 
circuit problems could also apply to other breakers that use automatic
 
closing logic, such as load-sequencing
 
breakers and offsite supply breakers to the emergency
 
buses.The information
 
herein is being provided as an early notification
 
of a potentially
 
significant
 
matter that is still under consideration
 
by the NRC staff. If NRC evaluation
 
so indicates, specific licensee actions may be requested.
 
No specific action or written response is required by this information
 
notice.If you have any questions
 
about this matter, please contact one of the technical contacts listed below or the Regional Administrator
 
of the appropriate
 
regional office.Di rector Division of Operational
 
===Events Assessment===
Office of Nuclear Reactor Regulation
 
Technical
 
Contacts:
James Lazevnick, NRR (301) 492-0814 Carl Schulten, NRR (301) 492-1192 Fred Burrows, NRR (301) 492-0783 Attachment:
List of Recently Issued NRC Information
 
Notices
 
Att"aant IN 88-75 September
 
16, 1988 Page I of I LIST OF RECENTLY ISSUED NRC INFORMATION
 
NOTICES Notice No. Subject Issuance 88-74 Potentially
 
Inadequate
 
9/14/88 Perfornance
 
of ECCS in PWRs During Recirculation
 
Operation
 
Following
 
a LOCA 88-73 Direction-Dependent
 
Leak 9/8/88 Characteristics
 
of Containment
 
Purge Valves 88-72 Inadequacies
 
in the Design 9/2/88 of dc Motor-Operated
 
Valves 88-71 Possible Environmental
 
9/1/88 Effect of the Reentry of COSMOS 1900 and Request for Collection
 
of Licensee Radioactivity
 
Measurements
 
Attributed
 
to That Event 88-70 Check Valve Inservice
 
8/29/88 Testing Program Deficiencies
 
88-69 Movable Contact Finger 8/19/88 Binding in HFA Relays Manufactured
 
by General Electric (GE)88-48, Licensee Report of Defective
 
8/24/88 Supplement
 
I Refurbished
 
Valves 88-68 Setpoint Testing of Pres- 8/22/88 surizer Safety Valves with Filled Loop Seals Using Hydraulic
 
Assist Devices 88P67- -P-F Zfiiairy Fiedeaer Pump 8/Z2j88 Turbine Overspeed
 
Trip Failure OL
 
* Operating
 
License CP
 
* Construction
 
Permit Issued to All holders of OLs or CPs for W and 8&W-designei
 
nuclear power reactors.All holders of 0Ls 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, fuel cycle licensees, and Priority I material licensees.
 
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._UNITED STATES NUCLEAR REGULATORY
 
COMMISSION
 
WASHINGTON, D.C. 20555 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, $300 FIRST CLASS MAIL POSTAGE & FEES PAID USNRC PERMIT No. 0-57 IN 88-75 September
 
16, 1988 When the Wolf Creek operator manually tripped the EDG output breaker, the auto-matic closing logic permissives
 
remained satisfied.
 
Therefore, the anti-pump relay remained energized, preventing
 
reclosure
 
of the circuit breaker. Cycling the EDG mode control switch at the local control station allowed the circuit breaker to reclose by momentarily
 
interrupting
 
the automatic
 
close signal, there-by resetting
 
the anti-pump
 
logic. When the mode switch contact was reclosed by returning
 
the switch to the "auto" position, the circuit breaker's
 
automatic closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in the control room to enable the operator to reclose the EDG circuit breaker from the control room. This switch was originally
 
intended only as a means of paralleling
 
the EDG with the offsite power supply. With the current modification, the switch can be used to reset the anti-pump
 
logic and allow the automatic
 
circuit to re-close the breaker. The modification
 
added a contact that is closed in the "normal" position and open in the "trip" and "pull to lock" positions
 
of the control switch.When operators
 
manually trip the EDG circuit breaker from this control switch, the contacts open to interrupt
 
the close circuit and reset the circuit breaker anti-pump
 
relay. If the operator wishes to keep the breaker open, he must put the switch in the "pull to lock" position.
 
Returning
 
the switch to the "normal" position completes
 
the automatic
 
close circuit and the breaker recloses.It should be noted that although the above discussion
 
has dealt only with EDG output circuit breakers, anti-pump
 
circuit problems could also apply to other breakers that use automatic
 
closing logic, such as load-sequencing
 
breakers and offsite supply breakers to the emergency
 
buses.The information
 
herein is being provided as an early notification
 
of a potentially
 
significant
 
matter that is still under consideration
 
by the NRC staff. If NRC evaluation
 
so indicates, specific licensee actions may be requested.
 
No specific action or written response is required by this information
 
notice.If you have any questions
 
about this matter, please contact one of the technical contacts listed below or the Regional Administrator
 
of the appropriate
 
regional office.Charles E. Rossi, Director Division of Operational
 
===Events Assessment===
Office of Nuclear Reactor Regulation
 
Technical
 
Contacts:
James Lazevnick, NRR (301) 492-0814 Carl Schulten, NRR (301) 492-1192 Fred Burrows, NRR (301) 492-0783 Attachment:
List of Recently Issued NRC Information
 
Notices*SEE PREVIOUS PAGE FOR CONCURRENCE
 
OFC *OEAB *Tech Ed *SL:OEAB *C:OEAB *D:DEST *C:OGCB NAME CSchulten
 
BCalure PBaranowsky
 
WLanning LShao CBerlinger
 
e l DATE 9/7/88 7/28/88 9/7/88 9/7/88 8/24/88 9/8/88 9/(,f 88 IN 88-September , 1988 contact was reclosed by returning
 
the switch to the "auto" position.
 
the circuit breaker's
 
automatic
 
closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in the control room to enable the operator to reclose the EDG circuit breaker from the control room. This switch was originally
 
intended only as a means of paralleling
 
the EDG with the offsite power supply. With the current modification.
 
the switch can be used to reset the anti-pump
 
logic and allow the automatic
 
circuit to reclose the breaker. The modification
 
added a contact that is closed in the "normal" position and open in the "trip" and"pull to lock" positions
 
of the control switch. When operators
 
manually trip the EDG circuit breaker from this control switch. the contacts open to interrupt
 
the close circuit and reset the circuit breaker anti-pump
 
relay.If the operator wishes to keep the breaker open. he must put the switch in the"pull to lock" position.
 
Returning
 
the switch to the "normal" position completes
 
the automatic
 
close circuit and the breaker recloses.It should be noted that although the above discussion
 
has dealt only with EDG output circuit breakers.
 
the anti-pump
 
circuit problem could also apply to other breakers that use automatic
 
closing logic, such as load-sequencing
 
breakers and offsite supply breakers to the emergency
 
buses.The information
 
herein is being provided as an early notification
 
of a potentially
 
significant
 
matter that is still under consideration
 
by the NRC staff. If NRC evaluation
 
so indicates.
 
specific licensee actions may be requested.
 
No specific action or written response is required by this information
 
notice. If you have any questions
 
about this matter, please contact any of the technical
 
contacts listed below or the Regional Administrator
 
of the appropriate
 
regional office.Charles E. Rossi, Director Division of Operational
 
===Events Assessment===
Office of Nuclear Reactor Regulation
 
Technical
 
Contacts:
James Lazevnick.
 
NRR (301) 492-0814 Carl Schulten.
 
NRR (301) 492-1192 Fred Burrows. NRR (301) 492-0783-e --- --:D: -NAME :CSchu Mn are :P aranowsky
 
:WLan n :LShao :CBeri nger :ERossi DATE q 88 /8 :1/88 /88 :18188 /88 OFFICIAL RECORD COPY
 
IN 88-August .1988 contact was reclosed by returning
 
the switch to the "auto" position.
 
the circuit breaker's
 
automatic
 
closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in the control room to enable the operator to reclose the EDG circuit breaker from the control room. This switch was originally
 
intended only as a means of paralleling
 
the EDG with the offsite power supply. With the current modification.
 
the switch can be used to reset the anti-pumping
 
logic and allow the automatic
 
circuit to reclose the breaker. The modification
 
added a contact that is closed in the "normal" position and open in the "trip" and"pull to lock" positions
 
of the control switch. When operators
 
manually trip the EDG circuit breaker from this control switch, the contacts open to interrupt
 
the close circuit and reset the circuit breaker anti-pumping
 
relay.If the operator wishes to keep the breaker open. he must put the switch in the"pull to lock" position.
 
Returning
 
the switch to the "normal" position completes
 
the automatic
 
close circuit and the breaker recloses.It should be noted that although the above discussion
 
has dealt only with EDG output circuit breakers, the same problem could also apply to other breakers that use automatic
 
closing logic, such as load-sequencing
 
breakers and offsite supply breakers to the emergency
 
buses.The information
 
herein is being provided as an early notification
 
of a potentially
 
significant
 
matter that is still under consideration
 
by the NRC staff. If NRC evaluation
 
so indicates.
 
specific licensee actions may be requested.
 
No specific action or written responses
 
is required by this information
 
notice. If you have any questions
 
about this matter, please contact either the technical
 
contacts listed below or the Regional Administrator
 
of the appropriate
 
regional office.Charles E. Rossi. Director Division of Operational
 
===Events Assessment===
Office of Nuclear Reactor Regulation
 
Technical
 
Contact: James Lazevnick.
 
NRR (301) 492-0814 Carl Schulten.
 
NRR (301) 492-1192 Fred Burrows. NRR (301) 492-0783 OFC _: T EOGCB :D:DOEA t "4i> -:-8{tjA---:-4og-yF---:---4-----------------
:-----------
NAME :CSchulten
 
:B& lure :PB pnowsky :WLanni:LS


==Description of Circumstances==
:CBerlinger
:On June 5, 1988, operators at Browns Ferry Unit 3 were unable to reclose thediesel generator output breakers to the 4-kV shutdown boards from the controlroom during a loss-of-power/loss-of-coolant-accident (LOP/LOCA) test. Duringthe test, the output breakers connected the diesel generators to their respec-tive 4-kV shutdown boards after the LOP signal was generated; however, thebreakers tripped and remained open after receiving the LOCA signal. Operatorsdiagnosed the output breaker lockout problem using system electrical configu-ration drawings. An operator was sent to the 4-kY shutdown board to manuallytransfer output breaker control power to its alternate source. This momentarilyremoved power, enabling the breaker to close when the power was restored.On October 14, 1987, an operator at Wolf Creek Generating Station manuallytripped the output circuit breaker of the emergency diesel generator (EDG)from the control room. At the time, the EDG was supplying a vital bus. Whenthe operators tried to reenergize the vital bus from the still-operating EDG,they found that they could not close the EDG output breaker from the controlroom. The vital bus was finally reenergized from the offsite power supply.Through examination of the breaker control schematics the licensee laterfound that the EDG circuit breaker could be closed by cycling the EDG modeswitch at the EDG local control station.880920197 IN 88-75September 16, 1988 Discussion:The anti-pump circuit configuration will protect large breakers from rapidcycling and, under certain circumstances, will prevent breaker closure. AtBrowns Ferry Unit 3, a unique sequence of events, a LOP signal followed within6 seconds by a LOCA signal, led to the discovery of a design deficiency of thiscircuit configuration. Contacts from the undervoltage relay will seal in thebreaker anti-pump relay until the undervoltage condition on the 4-kV boardsclears.The circuit is designed such that following a LOP, the undervoltage conditionmust exist for at least 5 seconds and the diesel. must reach rated speed beforethe diesel generator output breaker will close on the bus. Once the breakerhas closed, the closure spring recharge motor and the breaker anti-pump relaywill be energized. A fully discharged closure spring requires 2 seconds forthe spring to be fully recharged. During this 2 second window the anti-pumpcoil will remain energized via contacts sensing spring position, and if anundervoltage condition exists on the 4-kY bus it will seal in and lock openthe breaker.During the Browns Ferry event, the EDG output breaker closed 5 seconds afterthe LOP signal, the undervoltage condition was eliminated, and the undervoltagerelay began its 5 second cycle to reset from the undervoltage condition. About1.5 seconds 1ater. the. LOCA-signaL-retr-ipped-the-breaker-and-created-another--undervoltage condition on the 4-kV bus. At this point, because the undervoltagerelay had not completed its reset cycle, the undervoltage relay remained in itsundervoltage state. Therefore, the undervoltage relay sealed in the still-energized anti-pump relay because the undervoltage condition occurred beforethe breaker charging spring was fully charged. Thus, the breaker could notbe closed from the control room either manually or automatically until controlpower was removed, which deenergized the anti-pump relay.The Browns Ferry licensee modified the breaker control logic to prevent the anti-pump relay from sealing in during a LOCA condition by adding a time-delay relayin the breaker trip coil circuitry. This relay will be energized by a LOCAsignal and its contact in the anti-pump coil seal-in path will open after a2-to 5-second delay to prevent anti-pump coil seal-in and breaker lockout.The Wolf Creek EDG output circuit breaker has automatic closing logic to closethe circuit breaker when the following five permissives are satisfied:(1) Both offsite circuit breakers are open'(2 The EDG mode switch is in the automatic mode.(3 Lockout relays are deenergized.(4 A 3-second time delay has elapsed.(5) The EDG has reached operating speed and voltage.This logic sends a constant close signal to the circuit breaker that keeps thebreaker's internal anti-pump relay energized as long as the logic permissivesare satisfied. The anti-pump relay prevents the circuit breaker from cyclingif attempts are made to hold the breaker closed against a valid trip signal.I',
IN 88-75September 16, 1988 When the Wolf Creek operator manually tripped the EDG output breaker, the auto-matic closing logic permissives remained satisfied. Therefore, the anti-pumprelay remained energized, preventing reclosure of the circuit breaker. Cyclingthe EDG mode control switch at the local control station allowed the circuitbreaker to reclose by momentarily interrupting the automatic close signal, there-by resetting the anti-pump logic. When the mode switch contact was reclosed byreturning the switch to the "auto' position, the circuit breaker's automaticclosing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in thecontrol room to enable the operator to reclose the EDG circuit breaker from thecontrol room. This switch was originally intended only as a means of parallelingthe EDG with the offsite power supply. With the current modification, the switchcan be used to reset the anti-pump logic and allow the automatic circuit to re-close the breaker. The modification added a contact that is closed in the "normal"position and open in the "trip" and "pull to lock" positions of the control switch.When operators manually trip the EDG circuit breaker from this control switch,the contacts open to interrupt the close circuit and reset the circuit breakeranti-pump relay. If the operator wishes to keep the breaker open, he must putthe switch in the "pull to lock" position. Returning the switch to the "normal"position completes the automatic close circuit and the breaker recloses.It should be noted that although the above discussion has dealt only with EDGoutput- circuit breakers, anti-pump circuit problems could also apply to otherbreakers that use automatic closing logic, such as load-sequencing breakersand offsite supply breakers to the emergency buses.The information herein is being provided as an early notification of a potentiallysignificant matter that is still under consideration by the NRC staff. If NRCevaluation so indicates, specific licensee actions may be requested.No specific action or written response is required by this information notice.If you have any questions about this matter, please contact one of the technicalcontacts listed below or the Regional Administrator of the appropriate regionaloffice.Di rectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical Contacts: James Lazevnick, NRR(301) 492-0814Carl Schulten, NRR(301) 492-1192Fred Burrows, NRR(301) 492-0783Attachment:List of Recently Issued NRC Information Notices


Att"aantIN 88-75September 16, 1988Page I of ILIST OF RECENTLY ISSUEDNRC INFORMATION NOTICESNotice No. Subject Issuance88-74 Potentially Inadequate 9/14/88Perfornance of ECCS inPWRs During RecirculationOperation Following a LOCA88-73 Direction-Dependent Leak 9/8/88Characteristics ofContainment Purge Valves88-72 Inadequacies in the Design 9/2/88of dc Motor-Operated Valves88-71 Possible Environmental 9/1/88Effect of the Reentryof COSMOS 1900 andRequest for Collectionof Licensee RadioactivityMeasurements Attributedto That Event88-70 Check Valve Inservice 8/29/88Testing ProgramDeficiencies88-69 Movable Contact Finger 8/19/88Binding in HFA RelaysManufactured by GeneralElectric (GE)88-48, Licensee Report of Defective 8/24/88Supplement I Refurbished Valves88-68 Setpoint Testing of Pres- 8/22/88surizer Safety Valves withFilled Loop Seals UsingHydraulic Assist Devices88P67- -P-F Zfiiairy Fiedeaer Pump 8/Z2j88Turbine Overspeed TripFailureOL
:ERossi DATE 1&/ : //88 F./ A1/88 1.V 1.8 8 4f8 8 8 DAT O F:I g/ECORD : / /88COPY OFFICIAL RECORD COPY


* Operating LicenseCP
NRC INFO NOTICE 88-XX. DIESEL GENERATOR


* Construction PermitIssued toAll holders of OLsor CPs for W and8&W-designei nuclearpower reactors.All holders of 0Lsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors, fuelcycle licensees,and Priority Imaterial licensees.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors.All holders of OLsor CPs for nuclearpower reactors._UNITED STATESNUCLEAR REGULATORY COMMISSIONWASHINGTON, D.C. 20555OFFICIAL BUSINESSPENALTY FOR PRIVATE USE, $300FIRST CLASS MAILPOSTAGE & FEES PAIDUSNRCPERMIT No. 0-57 IN 88-75September 16, 1988 When the Wolf Creek operator manually tripped the EDG output breaker, the auto-matic closing logic permissives remained satisfied. Therefore, the anti-pumprelay remained energized, preventing reclosure of the circuit breaker. Cyclingthe EDG mode control switch at the local control station allowed the circuitbreaker to reclose by momentarily interrupting the automatic close signal, there-by resetting the anti-pump logic. When the mode switch contact was reclosed byreturning the switch to the "auto" position, the circuit breaker's automaticclosing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in thecontrol room to enable the operator to reclose the EDG circuit breaker from thecontrol room. This switch was originally intended only as a means of parallelingthe EDG with the offsite power supply. With the current modification, the switchcan be used to reset the anti-pump logic and allow the automatic circuit to re-close the breaker. The modification added a contact that is closed in the "normal"position and open in the "trip" and "pull to lock" positions of the control switch.When operators manually trip the EDG circuit breaker from this control switch,the contacts open to interrupt the close circuit and reset the circuit breakeranti-pump relay. If the operator wishes to keep the breaker open, he must putthe switch in the "pull to lock" position. Returning the switch to the "normal"position completes the automatic close circuit and the breaker recloses.It should be noted that although the above discussion has dealt only with EDGoutput circuit breakers, anti-pump circuit problems could also apply to otherbreakers that use automatic closing logic, such as load-sequencing breakersand offsite supply breakers to the emergency buses.The information herein is being provided as an early notification of a potentiallysignificant matter that is still under consideration by the NRC staff. If NRCevaluation so indicates, specific licensee actions may be requested.No specific action or written response is required by this information notice.If you have any questions about this matter, please contact one of the technicalcontacts listed below or the Regional Administrator of the appropriate regionaloffice.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical Contacts: James Lazevnick, NRR(301) 492-0814Carl Schulten, NRR(301) 492-1192Fred Burrows, NRR(301) 492-0783Attachment: List of Recently Issued NRC Information Notices*SEE PREVIOUS PAGE FOR CONCURRENCEOFC *OEAB *Tech Ed *SL:OEAB *C:OEAB *D:DEST *C:OGCBNAME CSchulten BCalure PBaranowsky WLanning LShao CBerlinger e lDATE 9/7/88 7/28/88 9/7/88 9/7/88 8/24/88 9/8/88 9/(,f 88 IN 88-September , 1988 contact was reclosed by returning the switch to the "auto" position. thecircuit breaker's automatic closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in thecontrol room to enable the operator to reclose the EDG circuit breaker fromthe control room. This switch was originally intended only as a means ofparalleling the EDG with the offsite power supply. With the currentmodification. the switch can be used to reset the anti-pump logic and allowthe automatic circuit to reclose the breaker. The modification added acontact that is closed in the "normal" position and open in the "trip" and"pull to lock" positions of the control switch. When operators manually tripthe EDG circuit breaker from this control switch. the contacts open tointerrupt the close circuit and reset the circuit breaker anti-pump relay.If the operator wishes to keep the breaker open. he must put the switch in the"pull to lock" position. Returning the switch to the "normal" positioncompletes the automatic close circuit and the breaker recloses.It should be noted that although the above discussion has dealt only with EDGoutput circuit breakers. the anti-pump circuit problem could also apply to otherbreakers that use automatic closing logic, such as load-sequencing breakers andoffsite supply breakers to the emergency buses.The information herein is being provided as an early notification of apotentially significant matter that is still under consideration by the NRCstaff. If NRC evaluation so indicates. specific licensee actions may berequested.No specific action or written response is required by this informationnotice. If you have any questions about this matter, please contact any of thetechnical contacts listed below or the Regional Administrator of the appropriateregional office.Charles E. Rossi, DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor RegulationTechnical Contacts: James Lazevnick. NRR(301) 492-0814Carl Schulten. NRR(301) 492-1192Fred Burrows. NRR(301) 492-0783-e --- --:D: -NAME :CSchu Mn are :P aranowsky :WLan n :LShao :CBeri nger :ERossiDATE q 88 /8 :1/88 /88 :18188 /88OFFICIAL RECORD COPY
===CIRCUIT BREAKERS FAIL TO AUTOMATICALLY===
CLOSE OFC :OEAB :Te h Ed :SL:OEAB :C:OEAb :L:SELB :C:OGCB :D:DUEA NAME :CSchulten


IN 88-August .1988 contact was reclosed by returning the switch to the "auto" position. thecircuit breaker's automatic closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in thecontrol room to enable the operator to reclose the EDG circuit breaker fromthe control room. This switch was originally intended only as a means ofparalleling the EDG with the offsite power supply. With the currentmodification. the switch can be used to reset the anti-pumping logic and allowthe automatic circuit to reclose the breaker. The modification added acontact that is closed in the "normal" position and open in the "trip" and"pull to lock" positions of the control switch. When operators manually tripthe EDG circuit breaker from this control switch, the contacts open tointerrupt the close circuit and reset the circuit breaker anti-pumping relay.If the operator wishes to keep the breaker open. he must put the switch in the"pull to lock" position. Returning the switch to the "normal" positioncompletes the automatic close circuit and the breaker recloses.It should be noted that although the above discussion has dealt only with EDGoutput circuit breakers, the same problem could also apply to other breakersthat use automatic closing logic, such as load-sequencing breakers and offsitesupply breakers to the emergency buses.The information herein is being provided as an early notification of apotentially significant matter that is still under consideration by the NRCstaff. If NRC evaluation so indicates. specific licensee actions may berequested.No specific action or written responses is required by this informationnotice. If you have any questions about this matter, please contact either thetechnical contacts listed below or the Regional Administrator of the appropriateregional office.Charles E. Rossi. DirectorDivision of Operational Events AssessmentOffice of Nuclear Reactor Regulation
lure :PBaranowsky


===Technical Contact:===
:WLanning
James Lazevnick. NRR(301) 492-0814Carl Schulten. NRR(301) 492-1192Fred Burrows. NRR(301) 492-0783OFC _: T EOGCB :D:DOEAt "4i> -:-8{tjA---:-4og-yF---:---4----------------- :-----------NAME :CSchulten :B& lure :PB pnowsky :WLanni:LS :CBerlinger :ERossiDATE 1&/ : //88 F./ A1/88 1.V1.88  4f8 8 8DAT O F:I g/ECORD : / /88COPYOFFICIAL RECORD COPY


NRC INFO NOTICE 88-XX. DIESEL GENERATOR CIRCUIT BREAKERS FAIL TO AUTOMATICALLYCLOSEOFC :OEAB :Te h Ed :SL:OEAB :C:OEAb :L:SELB :C:OGCB :D:DUEANAME :CSchulten lure :PBaranowsky :WLanning :FRosa :CBerlinger :ERosslDATE : / 88 /88 : I /88 / /88 : / /88 : / /88OFFICIAL RECORD COPY
:FRosa :CBerlinger


}}
:ERossl DATE : / 88 /88 : I /88 / /88 : / /88 : / /88 OFFICIAL RECORD COPY}}


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

Revision as of 13:37, 31 August 2018

Disabling of Diesel Generator Output Circuit Breakers by Anti-Pump Circuitry
ML031150110
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, 05000000, Zimmer, Fort Saint Vrain, Shoreham, Satsop, Trojan, Atlantic Nuclear Power Plant
Issue date: 09/16/1988
From: Rossi C E
Office of Nuclear Reactor Regulation
To:
References
IN-88-075, NUDOCS 8809120197
Download: ML031150110 (8)
v • d • e


I UNITED STATES NUCLEAR REGULATORY

COMMISSION

OFFICE OF NUCLEAR REACTOR REGULATION

WASHINGTON, D.C. 20555 September

16, 1988 NRC INFORMATION

NOTICE NO. 88-75: DISABLING

OF DIESEL GENERATOR

OUTPUT CIRCUIT BREAKERS BY ANTI-PUMP

CIRCUITRY

Addressees

All holders of operating

licenses or construction

permits for nuclear power reactors.

Purpose

This information

notice is being provided to alert addressees

to potential problems where the capability

to either automatically

or manually close diesel generator

circuit breakers from the control room may be lost. 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 do not constitute

NRC requirements;

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

of Circumstances:

On June 5, 1988, operators

at Browns Ferry Unit 3 were unable to reclose the diesel generator

output breakers to the 4-kV shutdown boards from the control room during a loss-of-power/loss-of-coolant-accident (LOP/LOCA)

test. During the test, the output breakers connected

the diesel generators

to their respec-tive 4-kV shutdown boards after the LOP signal was generated;

however, the breakers tripped and remained open after receiving

the LOCA signal. Operators diagnosed

the output breaker lockout problem using system electrical

configu-ration drawings.

An operator was sent to the 4-kY shutdown board to manually transfer output breaker control power to its alternate

source. This momentarily

removed power, enabling the breaker to close when the power was restored.On October 14, 1987, an operator at Wolf Creek Generating

Station manually tripped the output circuit breaker of the emergency

diesel generator (EDG)from the control room. At the time, the EDG was supplying

a vital bus. When the operators

tried to reenergize

the vital bus from the still-operating

EDG, they found that they could not close the EDG output breaker from the control room. The vital bus was finally reenergized

from the offsite power supply.Through examination

of the breaker control schematics

the licensee later found that the EDG circuit breaker could be closed by cycling the EDG mode switch at the EDG local control station.880920197 IN 88-75 September

16, 1988 Discussion:

The anti-pump

circuit configuration

will protect large breakers from rapid cycling and, under certain circumstances, will prevent breaker closure. At Browns Ferry Unit 3, a unique sequence of events, a LOP signal followed within 6 seconds by a LOCA signal, led to the discovery

of a design deficiency

of this circuit configuration.

Contacts from the undervoltage

relay will seal in the breaker anti-pump

relay until the undervoltage

condition

on the 4-kV boards clears.The circuit is designed such that following

a LOP, the undervoltage

condition must exist for at least 5 seconds and the diesel. must reach rated speed before the diesel generator

output breaker will close on the bus. Once the breaker has closed, the closure spring recharge motor and the breaker anti-pump

relay will be energized.

A fully discharged

closure spring requires 2 seconds for the spring to be fully recharged.

During this 2 second window the anti-pump coil will remain energized

via contacts sensing spring position, and if an undervoltage

condition

exists on the 4-kY bus it will seal in and lock open the breaker.During the Browns Ferry event, the EDG output breaker closed 5 seconds after the LOP signal, the undervoltage

condition

was eliminated, and the undervoltage

relay began its 5 second cycle to reset from the undervoltage

condition.

About 1.5 seconds 1ater. the. LOCA-signaL-retr-ipped-the-breaker-and-created-another--

undervoltage

condition

on the 4-kV bus. At this point, because the undervoltage

relay had not completed

its reset cycle, the undervoltage

relay remained in its undervoltage

state. Therefore, the undervoltage

relay sealed in the still-energized

anti-pump

relay because the undervoltage

condition

occurred before the breaker charging spring was fully charged. Thus, the breaker could not be closed from the control room either manually or automatically

until control power was removed, which deenergized

the anti-pump

relay.The Browns Ferry licensee modified the breaker control logic to prevent the anti-pump relay from sealing in during a LOCA condition

by adding a time-delay

relay in the breaker trip coil circuitry.

This relay will be energized

by a LOCA signal and its contact in the anti-pump

coil seal-in path will open after a 2-to 5-second delay to prevent anti-pump

coil seal-in and breaker lockout.The Wolf Creek EDG output circuit breaker has automatic

closing logic to close the circuit breaker when the following

five permissives

are satisfied:

(1) Both offsite circuit breakers are open'(2 The EDG mode switch is in the automatic

mode.(3 Lockout relays are deenergized.

(4 A 3-second time delay has elapsed.(5) The EDG has reached operating

speed and voltage.This logic sends a constant close signal to the circuit breaker that keeps the breaker's

internal anti-pump

relay energized

as long as the logic permissives

are satisfied.

The anti-pump

relay prevents the circuit breaker from cycling if attempts are made to hold the breaker closed against a valid trip signal.I',

IN 88-75 September

16, 1988 When the Wolf Creek operator manually tripped the EDG output breaker, the auto-matic closing logic permissives

remained satisfied.

Therefore, the anti-pump relay remained energized, preventing

reclosure

of the circuit breaker. Cycling the EDG mode control switch at the local control station allowed the circuit breaker to reclose by momentarily

interrupting

the automatic

close signal, there-by resetting

the anti-pump

logic. When the mode switch contact was reclosed by returning

the switch to the "auto' position, the circuit breaker's

automatic closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in the control room to enable the operator to reclose the EDG circuit breaker from the control room. This switch was originally

intended only as a means of paralleling

the EDG with the offsite power supply. With the current modification, the switch can be used to reset the anti-pump

logic and allow the automatic

circuit to re-close the breaker. The modification

added a contact that is closed in the "normal" position and open in the "trip" and "pull to lock" positions

of the control switch.When operators

manually trip the EDG circuit breaker from this control switch, the contacts open to interrupt

the close circuit and reset the circuit breaker anti-pump

relay. If the operator wishes to keep the breaker open, he must put the switch in the "pull to lock" position.

Returning

the switch to the "normal" position completes

the automatic

close circuit and the breaker recloses.It should be noted that although the above discussion

has dealt only with EDG output- circuit breakers, anti-pump

circuit problems could also apply to other breakers that use automatic

closing logic, such as load-sequencing

breakers and offsite supply breakers to the emergency

buses.The information

herein is being provided as an early notification

of a potentially

significant

matter that is still under consideration

by the NRC staff. If NRC evaluation

so indicates, specific licensee actions may be requested.

No specific action or written response is required by this information

notice.If you have any questions

about this matter, please contact one of the technical contacts listed below or the Regional Administrator

of the appropriate

regional office.Di rector Division of Operational

Events Assessment

Office of Nuclear Reactor Regulation

Technical

Contacts:

James Lazevnick, NRR (301) 492-0814 Carl Schulten, NRR (301) 492-1192 Fred Burrows, NRR (301) 492-0783 Attachment:

List of Recently Issued NRC Information

Notices

Att"aant IN 88-75 September

16, 1988 Page I of I LIST OF RECENTLY ISSUED NRC INFORMATION

NOTICES Notice No. Subject Issuance 88-74 Potentially

Inadequate

9/14/88 Perfornance

of ECCS in PWRs During Recirculation

Operation

Following

a LOCA 88-73 Direction-Dependent

Leak 9/8/88 Characteristics

of Containment

Purge Valves 88-72 Inadequacies

in the Design 9/2/88 of dc Motor-Operated

Valves 88-71 Possible Environmental

9/1/88 Effect of the Reentry of COSMOS 1900 and Request for Collection

of Licensee Radioactivity

Measurements

Attributed

to That Event 88-70 Check Valve Inservice

8/29/88 Testing Program Deficiencies

88-69 Movable Contact Finger 8/19/88 Binding in HFA Relays Manufactured

by General Electric (GE)88-48, Licensee Report of Defective

8/24/88 Supplement

I Refurbished

Valves 88-68 Setpoint Testing of Pres- 8/22/88 surizer Safety Valves with Filled Loop Seals Using Hydraulic

Assist Devices 88P67- -P-F Zfiiairy Fiedeaer Pump 8/Z2j88 Turbine Overspeed

Trip Failure OL

  • Operating

License CP

  • Construction

Permit Issued to All holders of OLs or CPs for W and 8&W-designei

nuclear power reactors.All holders of 0Ls 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, fuel cycle licensees, and Priority I material licensees.

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._UNITED STATES NUCLEAR REGULATORY

COMMISSION

WASHINGTON, D.C. 20555 OFFICIAL BUSINESS PENALTY FOR PRIVATE USE, $300 FIRST CLASS MAIL POSTAGE & FEES PAID USNRC PERMIT No. 0-57 IN 88-75 September

16, 1988 When the Wolf Creek operator manually tripped the EDG output breaker, the auto-matic closing logic permissives

remained satisfied.

Therefore, the anti-pump relay remained energized, preventing

reclosure

of the circuit breaker. Cycling the EDG mode control switch at the local control station allowed the circuit breaker to reclose by momentarily

interrupting

the automatic

close signal, there-by resetting

the anti-pump

logic. When the mode switch contact was reclosed by returning

the switch to the "auto" position, the circuit breaker's

automatic closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in the control room to enable the operator to reclose the EDG circuit breaker from the control room. This switch was originally

intended only as a means of paralleling

the EDG with the offsite power supply. With the current modification, the switch can be used to reset the anti-pump

logic and allow the automatic

circuit to re-close the breaker. The modification

added a contact that is closed in the "normal" position and open in the "trip" and "pull to lock" positions

of the control switch.When operators

manually trip the EDG circuit breaker from this control switch, the contacts open to interrupt

the close circuit and reset the circuit breaker anti-pump

relay. If the operator wishes to keep the breaker open, he must put the switch in the "pull to lock" position.

Returning

the switch to the "normal" position completes

the automatic

close circuit and the breaker recloses.It should be noted that although the above discussion

has dealt only with EDG output circuit breakers, anti-pump

circuit problems could also apply to other breakers that use automatic

closing logic, such as load-sequencing

breakers and offsite supply breakers to the emergency

buses.The information

herein is being provided as an early notification

of a potentially

significant

matter that is still under consideration

by the NRC staff. If NRC evaluation

so indicates, specific licensee actions may be requested.

No specific action or written response is required by this information

notice.If you have any questions

about this matter, please contact one of the technical contacts listed below or the Regional Administrator

of the appropriate

regional office.Charles E. Rossi, Director Division of Operational

Events Assessment

Office of Nuclear Reactor Regulation

Technical

Contacts:

James Lazevnick, NRR (301) 492-0814 Carl Schulten, NRR (301) 492-1192 Fred Burrows, NRR (301) 492-0783 Attachment:

List of Recently Issued NRC Information

Notices*SEE PREVIOUS PAGE FOR CONCURRENCE

OFC *OEAB *Tech Ed *SL:OEAB *C:OEAB *D:DEST *C:OGCB NAME CSchulten

BCalure PBaranowsky

WLanning LShao CBerlinger

e l DATE 9/7/88 7/28/88 9/7/88 9/7/88 8/24/88 9/8/88 9/(,f 88 IN 88-September , 1988 contact was reclosed by returning

the switch to the "auto" position.

the circuit breaker's

automatic

closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in the control room to enable the operator to reclose the EDG circuit breaker from the control room. This switch was originally

intended only as a means of paralleling

the EDG with the offsite power supply. With the current modification.

the switch can be used to reset the anti-pump

logic and allow the automatic

circuit to reclose the breaker. The modification

added a contact that is closed in the "normal" position and open in the "trip" and"pull to lock" positions

of the control switch. When operators

manually trip the EDG circuit breaker from this control switch. the contacts open to interrupt

the close circuit and reset the circuit breaker anti-pump

relay.If the operator wishes to keep the breaker open. he must put the switch in the"pull to lock" position.

Returning

the switch to the "normal" position completes

the automatic

close circuit and the breaker recloses.It should be noted that although the above discussion

has dealt only with EDG output circuit breakers.

the anti-pump

circuit problem could also apply to other breakers that use automatic

closing logic, such as load-sequencing

breakers and offsite supply breakers to the emergency

buses.The information

herein is being provided as an early notification

of a potentially

significant

matter that is still under consideration

by the NRC staff. If NRC evaluation

so indicates.

specific licensee actions may be requested.

No specific action or written response is required by this information

notice. If you have any questions

about this matter, please contact any of the technical

contacts listed below or the Regional Administrator

of the appropriate

regional office.Charles E. Rossi, Director Division of Operational

Events Assessment

Office of Nuclear Reactor Regulation

Technical

Contacts:

James Lazevnick.

NRR (301) 492-0814 Carl Schulten.

NRR (301) 492-1192 Fred Burrows. NRR (301) 492-0783-e --- --:D: -NAME :CSchu Mn are :P aranowsky

WLan n :LShao :CBeri nger :ERossi DATE q 88 /8 :1/88 /88 :18188 /88 OFFICIAL RECORD COPY

IN 88-August .1988 contact was reclosed by returning

the switch to the "auto" position.

the circuit breaker's

automatic

closing logic closed the breaker.The Wolf Creek licensee modified the EDG breaker control switch located in the control room to enable the operator to reclose the EDG circuit breaker from the control room. This switch was originally

intended only as a means of paralleling

the EDG with the offsite power supply. With the current modification.

the switch can be used to reset the anti-pumping

logic and allow the automatic

circuit to reclose the breaker. The modification

added a contact that is closed in the "normal" position and open in the "trip" and"pull to lock" positions

of the control switch. When operators

manually trip the EDG circuit breaker from this control switch, the contacts open to interrupt

the close circuit and reset the circuit breaker anti-pumping

relay.If the operator wishes to keep the breaker open. he must put the switch in the"pull to lock" position.

Returning

the switch to the "normal" position completes

the automatic

close circuit and the breaker recloses.It should be noted that although the above discussion

has dealt only with EDG output circuit breakers, the same problem could also apply to other breakers that use automatic

closing logic, such as load-sequencing

breakers and offsite supply breakers to the emergency

buses.The information

herein is being provided as an early notification

of a potentially

significant

matter that is still under consideration

by the NRC staff. If NRC evaluation

so indicates.

specific licensee actions may be requested.

No specific action or written responses

is required by this information

notice. If you have any questions

about this matter, please contact either the technical

contacts listed below or the Regional Administrator

of the appropriate

regional office.Charles E. Rossi. Director Division of Operational

Events Assessment

Office of Nuclear Reactor Regulation

Technical

Contact: James Lazevnick.

NRR (301) 492-0814 Carl Schulten.

NRR (301) 492-1192 Fred Burrows. NRR (301) 492-0783 OFC _: T EOGCB :D:DOEA t "4i> -:-8{tjA---:-4og-yF---:---4-----------------

-----------

NAME :CSchulten

B& lure :PB pnowsky :WLanni:LS
CBerlinger
ERossi DATE 1&/ : //88 F./ A1/88 1.V 1.8 8 4f8 8 8 DAT O F:I g/ECORD : / /88COPY OFFICIAL RECORD COPY

NRC INFO NOTICE 88-XX. DIESEL GENERATOR

CIRCUIT BREAKERS FAIL TO AUTOMATICALLY

CLOSE OFC :OEAB :Te h Ed :SL:OEAB :C:OEAb :L:SELB :C:OGCB :D:DUEA NAME :CSchulten

lure :PBaranowsky

WLanning
FRosa :CBerlinger
ERossl DATE : / 88 /88 : I /88 / /88 : / /88 : / /88 OFFICIAL RECORD COPY


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