ML20245B244
| ML20245B244 | |
| Person / Time | |
|---|---|
| Issue date: | 06/13/1989 |
| From: | Novak T NRC OFFICE FOR ANALYSIS & EVALUATION OF OPERATIONAL DATA (AEOD) |
| To: | Rossi C Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML20245B246 | List: |
| References | |
| AEOD-E905, NUDOCS 8906230095 | |
| Download: ML20245B244 (3) | |
Text
. _. _ - _ _
JUN 181989 MEMORANDUM FOR: Charles E. Rossi, Director 4
Division of Operational Events' Assessment Office of Nuclear Reactor Regulation l
FROM:
. Thomas M. Novak, Director Division of Safety Programs Office for Analysis and Evaluation i
of Operational' Data
SUBJECT:
ELECTRICAL BUS BAR FAILURES Enclosed is an. Engineering Evaluation report concerning certain failures of' electrical bus bars in medium voltage buses. These failures have resulted in bus bar electrical faults and fires, electrical power system undervoltage'condi-tions, plant transients, and reactor trips.
Failure.nf the bus bars has been attributed to cracking of the bus bar insu-lation combined with the presence of moisture or debris in the bus bar hous-ings, which jointly provide undesired tracking paths for electrical' faults.
It.is recommended that an NRC Information Notice (IN) should be sent to all licensees and construction permittees to alert them to these specific deficiencies which have occurred at a number of operating nuclear facilities. Accordingly, enclosed.is a proposed IN in this regard.
For further information regarding this study, please contact Mark Padovan (x24445) of my staff.
o
/s/
Thomas M. Novak, Director Division of Safety Programs Office for the Analysis and Evaluation of Operational Data
Enclosures:
As stated Distribution:
.p._...,.
- ,-CentralJFilea ROAB R/F WLanning DSP R/F CHeltemes MPadovan EJordan f]~"j Plam MTaylor, ED0 JRosenthal e90623co95 g 13 O/90 3
/
^
/
l BBrady
/
SEE PREVIOUS CONCURRENCE
- ROAB:DSP:AE0D*
ROAB:DSP:AEOD ROAB:DSP:AE0D*
DSP:AE0D*
LPadovan:mp:as Plam JRosenthal VBenaroya vak 5/01/89 5/01/89 5/ /89 5/ /89
///2/.89 Rile 70TEL K0M Ci M E!S
& l~
+
'w a
- l
$=,
6
'['
l MEMORANDUM ~FOR:i Charles E. Rossi Director Division of Operational Events Assessment Office-of Nuclear Reactor Regulation dh FROM:-
Thomas M. Novak, Director Division'of> Safety Programs e
Office for Analysis and Evaluation of-Operational Data
SUBJECT:
ELECTRICAL BUS BAR FAILURES
/
Enclosed 'is an' Engineering Evaluation report concerning certairytailures of-N' electrical, bus bars in' medium voltage buses. These failures have resulted in-bus bar, electrical faults and. fires, electrical; power system'undervoltage.condi -
tions, plant transients, and reactor' trips. The reactor tfips, in turn,' caused:
unnecessary challenges to plantJsafetyl systems.
j/
Failure of the bus bafs h'as been atitributed to crackiIg of the bus bar insu-lationLcombined with the presence of moisture or~ debris.in the: bus bar hous-
~
'ings, which joint 1. provide-undesired tracking paths for electrical faults.
L
~
/
c
- An NRClinformation notice (IN) should bessent,t'o all licensees and construction permitteesito alerttthem to these specific deficiencies which have occurrd observed at a number.'of operating nuclear facilities. "Accordingly, enclosed is:a' proposed IN11n..this regard;
/
/
+
For-further information regarding.this/5tudy, please contact Mark Padovan
-(x24445) of nty staff.
/
7
/
/
Thomas M. Novak, Director Division of Safety Programs.
/
Office-for the Analysis and Evaluation'
/
of 0perational Data
/[
Enclosures:
As stated
. Distribution:
-PDR Central File ROAB R/F WLanning
'DSP~R/F CHeltemes 1
'HPadovan EJordan MTaylor, ED0
.)
'Plam JRosenthal i
VBenaroya TNovak-KBlack BBrady SEE PREVIOUS CONCURRENCE
- JN ROAB:DSP:AEOD*
ROAB:DSP:AE0D ROAB:DSP:AE DSP:AE0D LPadovan:mp:as Plam JRosenthal VBenjiroya T vak 5/01/89 5/01/89 5//j89 5/h/89
/f$89 1
l u
h MEMORANDUM FOR: Charles E. Rossi,-Director Division of Operational Events Assessment Office of Nuclear Reactor Regulation FROM:
Thomas M. Novak, Director Division of Safety Programs l
Office for Analysis and. Evaluation of Operational Data i
SUBJECT:
ELECTRICAL BUS BAR FAILURES Enclosed is an Engineering Evaluation report concerning failures f electrical bus bars in medium voltage buses. 'These failures have resulted in bus bar electrical faults and fires, electrical power system undervolt ge conditions, plant transients, and reactor trips. The reactor trips, in t rn, caused unnecessary challenges to plant safety systems, and provide undesired oppr
-tunities for equipment malfunctions and operator errors.
Failure of the bus bars has been attributed to cracking f the bus bar insu-lation combined with the presence of moisture or debri in the bus bar hous-ings, which jointly provide undesired tracking paths or electrical faults.
AE0D suggests that.an NRC information notice (IN) e sent to all licensees and construction permittees to alert them to specifi deficiencies observed at a number of operating nuclear facilities. Accor ngly, enclosed is a proposed IN in this regard.
For further information regarding this stud, please contact Mark Padovan (x24445) of my staff. We shall be. pleased /to meet with you or your staff to discuss this report.
omas M. Novak, Director Division of Safety Programs Office for the Analysis and Evaluation of Operational Data
Enclosures:
As stated Distribution:
PDR Central File ROAB R/F WLa'nning DSP R/F C.Heltemes MPadovan EJordan Plam
<MTaylor, EDO JRosenthal VBenaroya TNovak KBlack BBrady l
y ROAB:DS.10DM]
ROAB:
D ROAB:DSP:AE0D DSP:AEOD D:AE0D LPadovan:mp:as PJ am Y%
JRosenthal VBenaroya TNovak 5/ol/89 Elg)/8 5/ /89 5/ /89 5/ /89 i
__ __ ________ _ _ _ _ _ _ _