Category:NRC Information Notice[Table view]The following query condition could not be considered due to this wiki's restrictions on query size or depth: <code> [[:Beaver Valley]] OR [[:Millstone]] OR [[:Hatch]] OR [[:Monticello]] OR [[:Calvert Cliffs]] OR [[:Dresden]] OR [[:Davis Besse]] OR [[:Peach Bottom]] OR [[:Browns Ferry]] OR [[:Salem]] OR [[:Oconee]] OR [[:Mcguire]] OR [[:Nine Mile Point]] OR [[:Palisades]] OR [[:Palo Verde]] OR [[:Perry]] OR [[:Indian Point]] OR [[:Fermi]] OR [[:Kewaunee]] OR [[:Catawba]] OR [[:Harris]] OR [[:Wolf Creek]] OR [[:Saint Lucie]] OR [[:Point Beach]] OR [[:Oyster Creek]] OR [[:Watts Bar]] OR [[:Hope Creek]] OR [[:Grand Gulf]] OR [[:Cooper]] OR [[:Sequoyah]] OR [[:Byron]] OR [[:Pilgrim]] OR [[:Arkansas Nuclear]] OR [[:Braidwood]] OR [[:Susquehanna]] OR [[:Summer]] OR [[:Prairie Island]] OR [[:Columbia]] OR [[:Seabrook]] OR [[:Brunswick]] OR [[:Surry]] OR [[:Limerick]] OR [[:North Anna]] OR [[:Turkey Point]] OR [[:River Bend]] OR [[:Vermont Yankee]] OR [[:Crystal River]] OR [[:Haddam Neck]] OR [[:Ginna]] OR [[:Diablo Canyon]] OR [[:Callaway]] OR [[:Vogtle]] OR [[:Waterford]] OR [[:Duane Arnold]] OR [[:Farley]] OR [[:Robinson]] OR [[:Clinton]] OR [[:South Texas]] OR [[:San Onofre]] OR [[:Cook]] OR [[:Comanche Peak]] OR [[:Yankee Rowe]] OR [[:Maine Yankee]] OR [[:Quad Cities]] OR [[:Humboldt Bay]] OR [[:La Crosse]] OR [[:Big Rock Point]] OR [[:Rancho Seco]] OR [[:Zion]] OR [[:Midland]] OR [[:Bellefonte]] OR [[:Fort Calhoun]] OR [[:FitzPatrick]] OR [[:McGuire]] OR [[:LaSalle]] OR [[:05000000]] OR [[:Zimmer]] OR [[:Fort Saint Vrain]] OR [[:Shoreham]] OR [[:Satsop]] OR [[:Trojan]] OR [[:Atlantic Nuclear Power Plant]] OR [[:Crane]] </code>.
All holders of operating licenses or construction permits for nuclear power
reactors.
Purpose
This information notice is being provided to alert addressees to an observed
practice in which vendors make changes to the performance characteristics of
molded-case circuit breakers without making any corresponding revisions to
the breaker part number. 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
During several inspections performed by the NRC, it was discovered that manu- facturers of molded case circuit breakers frequently altered the time-current
characteristic curves pertaining to a particular style or type of breaker.
These changes were made without changing the part number of the breaker and
often without any specific notification to the customer. The changes identi- fied during the NRC inspections ranged from very minor alterations to the
thermal portion of the curves to major alterations to the magnetic instanta- neous trip portion of the curves.
One change for ITE-type 100-amp breakers
involved the movement of the instantaneous band from 600-1000 amps to 1200-2000
amps. Although product literature usually contains the appropriate curves, the
curves are not routinely provided with the breakers.
Discussion:
As a result of these changes, many licensees who procure replacement breakers
by part number only are receiving breakers with performance characteristics
that may be different from those assumed in the original plant design. If the
breakers are not analyzed for performance characteristics, upon installation
these breakers potentially could degrade the electrical protection system
and/or cause premature tripping upon the energizing of vital safety-related
systems. Additionally, many perceived failures of circuit breakers detected
802
6
IN 89-21 February 27, 1989 during pre-installation or routine testing may actually be the result of un- known changes in time-current characteristic curves.
One way to ensure that
the breakers purchased conform to a particular curve would be to reference
the specific curve (including the applicable revision) as part of the purchase
requirements.
If the breaker was no longer manufactured to meet the specifi- cations of that specific curve, the new curve would have to be analyzed for
its effect on the overall system.
No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact the technical
contact listed below or the Regional Administrator of the appropriate regional
office.
arl
.
si, Director
Division of Operational Events Assessment
Office of Nuclear Reactor Regulation
Technical Contact:
J. B. Jacobson, NRR
(301) 492-0996 Attachment: List of Recently Issued NRC Information Notices
IN 89-21 February 27, 1989 during pre-installation or routine testing may actually be the result of un- known changes in time-current characteristic curves. One way to ensure that
the breakers purchased conform to a particular curve would be to reference
the specific curve (including the applicable revision) as part of the purchase
requirements. If the breaker was no longer manufactured to meet the specifi- cations of that specific curve, the new curve would have to be analyzed for
its effect on the overall system.
No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact the technical
contact 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:
J. B.
(301)
Jacobson, NRR
492-0996 Attachment:
List of Recently Issued NRC Information Notices
SEE PREVIOUS CONCURRENCES
D <
2/89
BC/AB:DRIS:NRR
EWBrach
02/07/89
C/OGCB:DOEA:NRR
CHBerlinger
02/09/89
BC/SELB:DEST:NRR
FRose
02/06/89
PPMB:ARM
TechEd
02/17/89
D/DRIS:NRR
BKGrimes
02/07/89
VIB:DRIS:NRR
JJacobson
01/30/89
SC/VIB:DRIS:NRR
UPotapovs
02/01/89
IN 89-XX
January XX, 1989 plant design. If unanalyzed, upon installation these breakers could
potenttally degrade the electrical protection system and/or cause premature
tripping upon energization of vital safety-related systems.
Additionally, many
perceived circuit breaker failures detected during pre-installation or routine
testing may actually be due to an unknown change in Time - Current
Characteristic Curves. One way to ensure that received breakers conform to a
particular curve would be to reference the specific curve (including revision
applicable) as part of the purchase requirements. If the breaker needed is no
longer manufactured to that specific curve, the new curve would need to be
analyzed for its effect on the overall system.
No specific action or written response is required by this information notice.
If you have any questions about this matter, please contact the technical
contact 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:
J. B. Jacobson, NRR
(301) 492-0996
See previous concurrence.
OFC
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NAME :JJacobson:nrp
UPotapovs*
EWBrach*
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DATE :01/30/89*
02/01/89
02/07/89
02/06/89
02/07/89
02i1 /89 OFC
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DATE
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DATE :02/ /89
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IN 89-XX
January XX, 1989 plant design. If unanalyzed, upon installation these breakers could
potentially degrade the electrical protection system and/or cause premature
trip ing upon energization of vital safety related systems. Additionally, many
perce ed circuit breaker failures detected during pre-installation or routine
testing ay actually be due to an unknown change in Time - Current
Characterstic Curves. One way to ensure that received breakers conform to a
particular urve would be to reference the specific curve (including revision
applicable)
part of the purchase requirements. If the breaker need
is no
longer manufac ured to that specific curve, the new curve would need o be
analyzed for it effect on the overall system. No specific actio
r written
response is requi ed by this information notice. If you have a
questions
about this matter, lease contact the technical contact liste
below or the
Regional Administrat r of the appropriate regional office.
Charles E.
i, Director
Division
Operational Events Assessment
Office o Nuclear Reactor Regulation
Technical Contact:
J. B. Jacobson, RR
(301) 492-0996
DISTRIBUTION
Central Files
VIB R/F
DRIS R/F
BKGrimes
EWBrach
UPotapovs
JJacobson
See pr
ious concurrence.
IB:D I
SC: VIB- IS
BC: TORIS
D- HERR
C:GCB
D:DDE
NAME
JJaco son:nrp
UPotap vs
EW')ch
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CBerlinger
CERo!
DATE
01
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02/
/89
02/2 /89
02/
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02/
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02/
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IN 89-XX
January XX 1989
Page 2 of
plant design. If analyzed, upon installation these breakers cou d
potentially degrade
e electrical protection system and/or caus premature
tripping upon energiza on of vital safety related systems. Ad tionally, many
perceived circuit breake failures detected during pre-install ion or routine
testing may actually be du to an unknown change in Time - Cu rent
Characteristic Curves.
One
y to ensure that received brea ers conform to a
particular curve would be to reference the specific curve ( ncluding Revision
applicable) as part of the purc se requirements. If the reaker needed is no
longer manufactured to that spec ic curve, the new curve ould need to be
analyzed for its effect on the ove
11 system. No speci ic action or written
response is required by this informa ion notice. If yo have any questions
about this matter, please contact the echnical contac listed below or the