ML20003D513
| ML20003D513 | |
| Person / Time | |
|---|---|
| Site: | Summer  |
| Issue date: | 03/20/1981 |
| From: | Nichols T SOUTH CAROLINA ELECTRIC & GAS CO. |
| To: | James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, NUDOCS 8103270540 | |
| Download: ML20003D513 (2) | |
Text
2 south CAROLINA ELECTRIC a gas COMPANY
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Mr. James P. O'Reilly, Director 9
U. S. Nuclear Regulatory Commission i4'
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Region II, Suite 3100 101 Marietta Street, N. W.
Atlanta, Georgia 30303
Subject:
Virgil C. Su=mer Nuclear Station Docket No. 50/395 Reportable Substantial Safety Hazard Final Report Nuclear Eng. File 3.1051
Dear Mr. O'Reilly:
On Thursday, February 19, 1981, a substantial safety hazard as defined by 10CFR21 was reported to Mr. Virgil Brownlee at NRC Region II Office. The item involved the 480 volt ITE breaker which failed to trip. Details are given on the attachment.
The item is being reported under our 10CFR50.55(e) procedure. This is considered a final report on the matter.
Very truly yours, T. C. Nichols, Jr.
TB:TCN:glb Attachment cc:
V. C. Summer w/o att.
J. B. Knotts, Jr.
G. H. Fischer w/o att.
J. L. Skolds T. C. Nichols, Jr. w/o att.
B. A. Burser O. W. Dixon, Jr.
O. S. Bradh.im C. A. Price Document Management Branch D. A. Nauman (55e/21/LER Only)
W. A. Williams, Jr.
I&E (Washington)
R. B. Clary ISEG A. R. Koon PRS off A. A. Smith NPCF H. N. Cyrus File 3
B. Watson fIil 5
8103 270 Syc
e FINAL REPORT 480 VOLT BREAKER FAILED TO TRIP 10CFR21 - SUBSTANTIAL SAFETY HAZARD 1.: Name and Address of Reporting Individual Tom Brewer South Carolina Electric & Gas Company Post Office Box 764 Columbia, South Carolina 29218 2.
Identification of Basic Component 480 Volt ITE Breaker 3.
Identification of Firm Supplying Component ITE Brown Boveri 4.
Nature of Defect, Substantial Safety Hazard Created, and Evaluation During testing of ITE breaker (MWR #51188 and #51189), as per partial disposition of NCN #99, it was discovered that the latch engagement
'a d tripper bar latch engagement were not properly adjusted on some n
- breakers. This condition causes the breakers to intermittently fail to trip on a fault condition. If the breaker doesn't trip, then the backup switchgear breaker will trip. Then all the equipment asso-ciated with 480 volt switchgear (XSW-lDB1) would trip off the line.
5.
Date Information of Defect Was Obtained - February 3,1981.
6.
Number and Location of Defect ISW-lDB1-7B Location AB 463 7.
Corrective Action A revision to EMP-405.2 has been generated to include additional inspection of the operating mechanism and adjustments, if necessary, and all breakers will be tested with ITE 504 tester and multi-amp tester. Two maintenance work requisitions 52633 and 52632 have been written so that all ITE switchgear in V. C. Summer Nuclear Plant will be retested.to correct for any improper breaker setting. The retesting is 40 percent complete and it is expected that 2 to 3 months time, all the ITE breakers will be retested to the new procedures.
8.
Advice to Purchasers or Licensees Nuclear Plant Nbintenance should perform all reasonable testing to assure proper operacion of-breakers even if similar tests are performed
- at the factory.
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