Part 21 Report - 1997-392
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
(p:\97byltrs\970126.wpf)
A Unicom Company
*** END OF DOCUMENT ***
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