United States Nuclear Regulatory Commission - Protecting People and the Environment


ACCESSION #:  9706050131

                       LICENSEE EVENT REPORT (LER)



FACILITY NAME:  BYRON NUCLEAR POWER STATION, UNIT 1        PAGE: 1 OF 5



DOCKET NUMBER:  05000454



TITLE:  INADEQUATE MANUFACTURER BREAKER REPAIR PROGRAM ALLOWED

        WRONG PARTS TO BE INSTALLED



EVENT DATE:  04/03/97   LER #:  97-008-00   REPORT DATE:  05/29/97



OTHER FACILITIES INVOLVED:  BYRON, UNIT 2           DOCKET NO:  05000455



OPERATING MODE:  1   POWER LEVEL:  100



THIS REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR

SECTION:

50.73(a)(2)(i)



LICENSEE CONTACT FOR THIS LER:

NAME:  Ronald Mancini, Station Support      TELEPHONE:  (815) 234-5441

       Engineering                                      X2478



COMPONENT FAILURE DESCRIPTION:

CAUSE:  E   SYSTEM:       COMPONENT:       MANUFACTURER:

REPORTABLE NPRDS:



SUPPLEMENTAL REPORT EXPECTED:  NO



ABSTRACT:



During offsite refurbishment of Safety Related Westinghouse [W120] DS-206

breakers [BKR], the manufacturer inadvertently replaced the breaker

closing springs with heavier duty closing springs.  Byron Station was

notified by the manufacturer, that five (5) DS-206 breakers had been

refurbished with the wrong closing springs.  Two (2) of the defective

breakers had been installed in the Ultimate Heat Sink (UHS) Essential

Service Water (SX) [BI] High Speed Fan Breaker Cubicles after being

returned to the Station.  Upon discovery, the defective breakers were

taken out of service, replaced with fully qualified breakers and the

defective breakers were placed on hold for return to the manufacturer.



The cause of the event was the manufacturer did not have an adequate

quality process in place to control the repair of Safety Related

breakers.  The manufacturer issued a stop work order prior to the

discovery of this event to stop the repair of breakers at their Lansing,

IL.  Facility.  Westinghouse has redirected their focus and attention in

establishing a high quality breaker refurbishment program, at the Lansing

facility.



Historically, due to the temporary declaration of inoperability for the

two SX fans, it was determined that on three (3) occasions, Byron Station

had more than the Technical Specification (TS) allowed number of SX fans

inoperable at a given time.  It was determined by Byron Station that this

event is reportable per 10CFR50.73(a)(2)(i)(B)-any operation or condition

prohibited by the plants Technical Specification.



There were no adverse consequences to the health and safety of the

general public or plant personnel as a result of this event.



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END OF ABSTRACT



TEXT                                                          PAGE 2 OF 5



A.   PLANT CONDITIONS PRIOR TO EVENT:



     Event Date/Time 04-03-97 / 1059



     Unit 1 Mode 1 PWR OP; Rx Power 100%; RCS [AB] Temperature/Pressure

     NOT/NOP



     Unit 1 Mode 2 PWR OP; Rx Power 100%; RCS [AB] Temperature/Pressure

     NOT/NOP



B.   DESCRIPTION OF EVENT:



     During the refurbishment of Safety Related Westinghouse [W120]

     DS-206 switch gear breakers [BKR] between 03/17/97 and 03/24/97, the

     manufacturer inadvertently replaced the breaker closing springs with

     heavier duty closing springs designed for use on DS-416 breakers.

     On 04/22/97, Byron Station requested that Westinghouse stop

     refurbishing Byron and Braidwood Stations breakers at their Lansing,

     IL.  facility until the manufacturer could resolve breaker concerns

     that had been previously identified with DS-206 breakers.  On

     04/23/97, Westinghouse issued a stop work order on the refurbishment

     of breakers at their Lansing, IL.  facility until all identified

     concerns could be resolved.  While Westinghouse was reviewing the

     breaker refurbishment activities in response to the stop work order,

     they discovered five breakers had been refurbished and returned to

     Byron Station with the wrong closing springs installed.



     The manufacturer issued internal nonconformance report number

     LFSO-97-010 on 04/30/97, notifying Byron Station that 5 breakers had

     been refurbished with the wrong closing springs.  The correct

     closing spring part number is 349A521G01.  The closing springs that

     were installed were part number 791A671G01.  The installed closing

     springs exert excessive force when closing due to increased spring

     strength.  Byron Station received the nonconformance report on

     05/01/97 and initiated Problem Identification Form B1997-01604 for

     the five breakers, shop order numbers, 02YN023B1-17, 02YN023BX1-2,

     02YN023BX1-10, 01YN027B1X2-2 and 02YN023B6X2-1.



     On 05/01/97, upon receipt of nonconformance report LFSO-97-010,

     Byron Engineering contacted Westinghouse and determined that if the

     breakers were currently in the open position and required to close,

     the breakers should be considered inoperable.  The engineering

     determination of inoperability was conservatively based on

     Westinghouse tests that demonstrated some cracking of the breaker

     pole base after 10 to 15 cycles.  A review of the maintenance

     records was performed and the installed locations of the 5 breakers

     with the incorrect springs were identified.  Two of the defective

     breakers were installed in the Essential Service Water (SX) [B1]

     High Speed Fan Breaker Cubicles 0SX03CA and 0SX03CB as temporary

     replacements.  The third defective breaker was installed in the SX

     [BI] Low Speed Fan Breaker Cubicle 0SX03CA as a temporary

     replacement.  The fourth defective breaker was installed in the

     breaker cubicle for the Auxiliary Building HVAC charcoal booster fan

     0VA03CA [VF].  The fifth defective breaker was installed in an

     unused spare breaker cubicle identified as 1AP12E-B and did not

     effect the operability of any plant equipment.



     For the purpose of this Licensee Event Report (LER) the event date

     was determined to be 04/03/97.  This date was when the first

     defective breaker was placed into service, rather than the first

     time that the three (3) SX High Speed Fan Technical Specification

     Breakers were considered inoperable on 04/10/97.  Additionally, the

     date of discovery was determined to be 05/01/97, which was when

     Byron Station was notified that five Safety Related breakers had

     been refurbished with the incorrect closing springs.



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TEXT                                                          PAGE 3 OF 5



B.   DESCRIPTION OF EVENT (cont.)



     The four defective breakers were installed in equipment feed

     cubicles and placed into service after receipt from the

     manufacturer.  This was done before it was identified that incorrect

     closing springs had been installed in the breakers.  The breakers

     were subsequently replaced with four fully qualified breakers.

     After determining the installed locations of the five (5) defective

     breakers, the breakers were immediately taken out of service to

     preclude their use and inadvertent cycling.  LCOAR 0BOS 7.5-1 a was

     also immediately entered due to the Technical Specification

     requirements for the SX High Speed Fans.  The immediate actions of

     removing the five breakers from service and entering LCOAR 0BOS

     7.5-1 a for the two (2) SX High Speed Fan breakers, conservatively

     ensured the SX system was within the allowances of the Byron Station

     Technical Specifications.  Additionally, by leaving the three (3)

     Non Technical Specification Breakers 0VA03CA, 0SX03CA Low Speed Fan

     and spare breaker 1AP12E-B out of service, plant and equipment

     safety were conservatively ensured until the breakers could be

     replaced with fully qualified breakers.  The breaker installations

     and subsequent replacements are as follows; Breaker 02YN023B1-17 was

     placed into service feeding the 0SX03CA High Speed Fan on 04/03/97,

     the breaker was replaced on 05/02/97.  Breaker 02YN023BX1-2 was

     placed into service feeding the 0SX03CB High Speed Fan on 04/04/97,

     the breaker was replaced on 05/03/97.  Breaker 02YN023BX1-10 was

     placed into service feeding the 0SX03CA low speed fan on 04/18/97,

     the breaker was replaced on 05/16/97.  Breaker 01YN027B1X2-2 was

     placed into service feeding fan 0VA03CA on 04/14/97, the breaker was

     replaced on 05/14/97.  Breaker 02YN023B6X2-1 that was placed into

     the unused spare cubicle was also removed on 05/16/97 for return to

     the manufacturer along with the other four breakers.



     A review of the stations out of service logs determined other

     Essential Service Cooling Tower High Speed Fans had been taken out

     of service between 04/03/97 and 05/01/97.  The review was performed

     to determine if the station should have entered Limiting Condition

     For Operation (LCOAR) 0BOS 7.5-1A since high speed fans 0SX03CA and

     0SX03CB were considered inoperable.  The review of the out of

     service log identified three occasions where a third SX High Speed

     Fan had been taken out of service (OOS) and LCOAR 0BOS 7.5-1 A would

     have been applicable.  On 04/10/97, fan 0SX03CC was out of service

     for preventive maintenance and surveillance activities.  On

     04/21/97, fan 0SX03CH was taken out of service for preventive

     maintenance activities.  On 04/22/97 and 04/23/97, fan 0SX03CE was

     out of service for preventive maintenance and surveillance

     activities.  The Technical Specification 3/4.7.5.b, Limiting

     Condition For Operation For Ultimate Heat Sink Cooling, requires 6

     of the 8 High Speed Fans to be operable or the following

     compensatory action be taken.  Action statement 3/4.7.5.b states,

     with only 5 fans operable, within 1 hour verify the 5 operable fans

     are capable of being powered by their respective emergency diesel

     generators.  The compensatory action was not verified because the

     station was unaware that the breakers in the 0SX03CA and 0SX03CB

     High Speed Fans were defective.  No other compensatory action was

     applicable because the unavailability of the third SX High Speed Fan

     for the three occasions was less than the 72 hour limiting

     condition.  Immediately upon discovery of the condition, Byron

     Station conservatively declared the two (2) affected SX fans

     inoperable.  Repair activities were initiated and all defective SX

     breakers and their associated fans were tested and verified to

     operate prior to the breakers being declared operable as part of

     post maintenance testing.



     The following are the dates when 3 breakers were out of service or

     inoperable causing the SX High Speed Fans to be inoperable.  On

     4/10/97, the OA, OB and OC SX High Speed Fans were inoperable.  On

     04/21/97, the OA, OB and OH SX High Speed Fans were inoperable.

     From 4/22/97 to 4/23/97, the OA, OB and OE SX High Speed Fans were

     inoperable.



     Since Byron Technical Specifications do not allow more than two (2)

     SX fans inoperable at a given time, this event is reportable per

     10CFR50.73(a)(2)(i)(B)-any operation or condition prohibited by the

     plants Technical Specification.



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TEXT                                                          PAGE 4 OF 5



C.   CAUSE OF EVENT:



     The cause of the event was the manufacturer did not have an adequate

     quality process in place to adequately control the refurbishment of

     the Safety Related breakers at the Lansing, IL.  facility,



D.   SAFETY ANALYSIS:



     Byron Station has judged that having three (3) SX High Speed Fans

     out of service during the short periods of time mentioned above, did

     not have a significant impact on overall plant safety.  At the

     listed times of SX fan inoperability, meteorological conditions did

     not exist at the Byron Station site which would have created a

     limiting design basis condition for the Byron Ultimate Heat Sink

     (UHS) due to Peak SX basin temperature.  A review of the Station

     outside air temperature data for 4/10, 4/21, 4/22, and 4/23/97

     indicates that the maximum air temperature was 55.7 degrees F.  This

     is well below the maximum wet bulb temperature (T sub wb) assumed in

     the design of UHS basin temperature analysis (T sub wb=70 degrees F

     for tower operation with SXCT Bypass valves open and T sub wb=82

     degrees F for the worst case 3 hour period).  The design basis

     analysis assumes two SX fans initially out of service and no cooling

     is assumed for the first 10 minutes of an event when the initial

     basin temperature is below 80 degrees F.  Based on Engineering

     Judgement, the improved tower cooling performance when operating at

     the lower wet bulb temperature would have offset the loss of cooling

     due to having an additional fan out of service.  Therefore, having

     the additional fan OOS for the three periods of time did not have a

     significant impact on plant safety.



     No equipment failure resulted from this event.  This event did not

     adversely affect any other system nor the operator's ability to

     maintain safe reactor plant conditions.  Therefore, there were no

     adverse consequences to the health and safety of the general public

     or plant personnel as a result of this event.



E.   CORRECTIVE ACTIONS:



     Westinghouse issued an internal nonconformance report number

     LFSO-97-010 on 04/30/97.  Byron Station was subsequently notified

     that five (5) breakers had been refurbished with the wrong closing

     springs.



     Upon receipt of the nonconformance report on 05/01/97, Byron

     Engineering contacted Westinghouse and determined the breakers

     should be considered inoperable.  The engineering determination was

     based on Westinghouse tests that demonstrated some cracking of the

     breaker pole base after 10 to 15 cycles.  Based on the engineering

     determination on 05/01/97, a review of the maintenance records was

     performed and the installed locations of the 5 breakers with the

     incorrect springs were identified.  After determining the installed

     locations of the five (5) defective breakers, the breakers were

     taken out of service to preclude their use and inadvertent cycling.

     Additionally, LCOAR 0BOS 7.5-1A was entered due to the Technical

     Specification requirements for the SX High Speed Fans 0SX03CA and

     0SX03CB being declared inoperable.  The five defective breakers have

     been replaced with fully qualified breakers and the defective

     breakers have been placed on hold for return to Westinghouse.



     Westinghouse issued a stop work order prior to the discovery of this

     event to stop the refurbishment of breakers at their Lansing, IL.

     facility, until all identified concerns could be resolved.

     Westinghouse redirected their focus and attention to establish high

     quality in the breaker refurbishment process at the Lansing

     facility.



     In addition, Westinghouse has notified the NRC under 10CFR21

     (c)(3)(i) on 05/14/97 of problems in their Safety Related circuit

     breaker program, specifically for ComEd's Byron and Braidwood

     Nuclear Sites.



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TEXT                                                          PAGE 5 OF 5



F.   RECURRING EVENTS SEARCH AND ANALYSIS:



     Database searches were performed for industry events in the "ALRA"

     database.  The key words "Breaker" and "Lansing" were used.  One

     document was identified and directly applied to the refurbishment of

     Byron Stations Breakers at the Lansing, IL.  facility.  Problem

     identification Form (PIF) B1997-01517 had been initiated by the

     Byron Station Component Engineer on 04/11/97, due to several

     concerns raised by a Westinghouse Engineer that was associated with

     the Byron and Braidwood Stations pilot breaker refurbishment program

     at the Lansing facility.  The concerns indicated a lack of a quality

     program being in place for the pilot breaker refurbishment program

     at the Lansing, IL.  facility.  The document identified several

     weaknesses including procedural steps not being adequately followed

     during the refurbishment of some of Byron Stations breakers.  The

     resultant action was the stop work order and review of the Lansing

     pilot breaker refurbishment program, which was issued by

     Westinghouse.  The consequent program review did identify wrong

     closing springs had been installed in five breakers for Byron

     Station, which resulted in nonconformance report LFSO-97-010 being

     issued and this Licensee Event Report.



     A search was performed in the "RABY" database.  The key word used

     was "breaker".  Eighty four documents were identified within the

     last 12 months associated with breakers at Byron Station.  Six

     additional events were identified documenting problems with breakers

     that were refurbished at the Lansing facility.  The PIF numbers are

     B1997-01364, B1997-01344, B1997-01178, B1997-00285, B1997-00084 and

     B1997-00083.  The six events identified process and program

     deficiencies at the Lansing, IL.  facility during breaker

     refurbishment for Byron Station.  The documents identified problems

     where breakers had been returned to the station with loose and

     broken parts, improper settings and parts being replaced with non

     like for like parts.  The six identified events were precursors to

     this event.  Corrective actions implemented by Westinghouse for the

     six precursor events were inadequate and did not prevent the wrong

     closing springs from being installed on the five breakers, The

     inadequate quality process failures that contributed to the six

     precursor events were used to support the Byron Station's request

     that Westinghouse issue a stop work order.



G.   COMPONENT FAILURE DATA:



     None.



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ATTACHMENT TO 9706050131                                      PAGE 1 OF 1



Commonwealth Edison Company

Byron Generating Station

4450 North German Church Road

Byron, IL 61010-9794

Tel 815-234-5441



May 28, 1997                                                        ComEd



LTR: BYRON 97-0126

FILE: 1.10.0101



U.S.  Nuclear Regulatory Commission

Document Control Desk

Washington, D.C.  20555



Dear Sir:



     The enclosed Licensee Event Report from Byron Generating Station is

being transmitted to you in accordance with the requirements of

10CFR50.73(a)(2)(ii).



     This report is number 97-008; Docket No.  50-454.



Sincerely,



K. L. Kofron

Station Manager

Byron Nuclear Power Station



KLK/RC/rp



Enclosure:     Licensee Event Report No.  97-008



cc:  A.  B.  Beach, NRC Region III Administrator

     NRC Senior Resident Inspector

     INPO Record Center

     ComEd Distribution List



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A Unicom Company



*** END OF DOCUMENT ***





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