ML20010C685
| ML20010C685 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 08/13/1981 |
| From: | Parker W DUKE POWER CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, SD-413-81-17, SD-414-81-17, NUDOCS 8108200310 | |
| Download: ML20010C685 (3) | |
Text
fi[
~
=
[
~
UEN7;g/ !!GIU N
' ' *3; r
- DUKE POWER COMPANY
'n, 1;;
Powsa Burtory a 42e Sourn.Cnuncu SrazzT, Cu HLOTTz, N, p. asa4a lORjf j1):. -0 &
s
~
Wer Perstoruv.
TcLtpwows:Anta 704 Svense Paoovction 13, 1981 373-4083 August J.I r
I
.Mr. James P.'0'Reilly,. Director i
Ub,I L 9
LU. S. Nuclear Regulatory Commission p
Region II y g jggj, ~-
101 Marietta Street, Suite 3100
- Atlanta, Georgia 30303
" W is's% ^
- N 7
. Catawba Nuclear. Station
'e,
Re:
lb [ -
Units 1 and 2 l
. Docket Nos. 50-413 and 50-414
Dear Mr.. O'Reilly:
. Pursuant to 10 CFR 50.55e, please find attached Significant Deficiency '
Report SD 413-414/81-17.
Very truly yours, a
William O. Parker, Jr.
~
RWO/php Attachment cc: Director Resident Inspector Office of Inspection and Enforcement Nuclear Regulatory Commission U. S. Nuclear Regulatory Commission Catawba Nuclear Station Washington, D. C. 20555 3 07 n
.s j
, ll
.S 1
m-
/
~
CATAWBA NUCLEAR STATION REPORT NUMBER: SD-413-414/81-17 REPORT DATE:-August 13, 1981 FACILITY: Catawba-Nuclear Station Station, Units 1 & 2 IDENTIFICATION OF DEFICIENCY:
In some Gould K-2000S and K-1600S load center breakers, evidence of contact between the mag latch lever and the right pole current sensor coil was ob-served.
Insulation dcmage can result on the coil if this condition is left uncorrected.
INITIAL REPORT:
On July 14, 1981, Mr Dennis Myers of the NRC, Region II, Atlanta, Georgia was notified of the deficiency by Mr R S Thompson, Mr L A Lecaros, and Mr W 0 Henry of Duke Power Co., Charlotte, NC 28242.
SUPPLIER AND/0R COMMENTS:
Brown Boveri Electric, Inc., Springhouse, Pennsylvania, manufactured the breakers which are used to supply the 600V auxiliary powcr to equipment used in various class 1E functions.
DESCRIPTION OF DEFICIENCY _:
During inspection of 600V switchgear breakers, evidence of contact between the mag latch lever and the right pole current sensor coil was observed in some breakers. The contact only occurs when the mag latch is activated by a fault indication. The problem is caused by an outside diameter of the coil which varies somewhat, and is, in some cases, too large for the space allowed by the breaker design. A second concern, also relating to the out-side diameters of current sensor coils, was discovered during this investi-gation.
In some cases, the coil.was observed to be in contact with the lower terminal current stud, directly behind-it. Although the coil is sufficiently insulated for the operating voltage between the two components, normal design practice would require additional insulation in the area of contact.
ANALYSIS OF SAFETY IMPLICATION:
Mag Latch Lever Clearance With repeated operations of the mag latch mechanism, insulation can be rubbed off of the sensor coil, exposing a small area of a conductor. Although the mag latch lever is at ground potential, contact with the coil would not pre--
vent the breaker from opening, since initiation of the tripping would occur prior to contact between the two components.
I p
~
R4 c -
ir e
Paga 2
~
Co'll damage observed.during inspection was not sufficient to prevent the equipment from performing its class lE function.
Lower Terminal Current Stud Clearance No impairment of the equipment to perform its safety related function is represented by the proximity of the current-sensor coil to the current. stud, since the coiliis sufficiently insulated for contact with this component, which is at 600V potential. The coil is Hi-Pot tested at 2200 volts.
CORRECTIVE ACTION:
Mag Latch Lever Clearance Gould K2000S and K1600S are to be inspected for contact between the mag latch lever and the current sensor coil.
If evidence of contact is found, clearance will be obtained by grinding the area of contact on the~ mag latch lever per instructions received from Brown Boveri.
Coils on which insula. tion damage is observed will be repaired, or replaced, depending upon the ev. tent of damage. Corrective actions are expected to be complete by November 11, 1981.
Lower Termina' Current Stud Clearance For breakers in which sensor coils are found to be in contact with the current stud, insulating tape will be applied to the stud surface in the area of con-tr.ct per instructions from Brown Boveri. Corrective actions are expected to be complete by November 11, 1981.
9 I
t
-