ML17244A743
| ML17244A743 | |
| Person / Time | |
|---|---|
| Site: | Ginna  |
| Issue date: | 06/25/1979 |
| From: | White L ROCHESTER GAS & ELECTRIC CORP. |
| To: | Grier B NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION I) |
| References | |
| NUDOCS 7908080671 | |
| Download: ML17244A743 (4) | |
Text
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I RAIC i"L.'Ilii!iÃirfifi'%l'l!IlliI'OCHESTER GAS AND ELECTRIC CORPORATIOV o
89 EAST AVENUE, ROCHESTER, II.Y. 14649 LEON D. WHITE. JR.
VICC PAESIDENT TCLCP>0'NE
- ac~ coos vie 546 2700 June 25, 1979 Mr. Boyce H. Grier, Director U. S. Nuclear Regulatory Commission Office of Inspection and Enforcement Region I 631 Park Avenue King of Prussia, Pennsylvania 19406
Subject:
IE.Bulletin No. 79-11, Faulty Overcurrent Trip Device in Circuit Breakers for Engineered Safety Systems R. E. Ginna Nuclear Power Plant, Unit gl Docket No. 50-244
Dear Mr. Grier:
In response to Inspection and Enforcement Bulletin 79-11 concerning overcurrent trip devices for Westinghouse type DB-75 and DB-50 circuit
- breakers, the following information is provided.
1.
There are numerous overcurrent devices of the subject type at Ginna Station.
2.
Test data taken since the overcurrent trip device testing and replacement program performed in response to IE Bulletin 73-01, Westinghouse DB-25, DB-50 and DB-75 Circuit Breaker Overcurrent Trip Devices, has been reviewed.
They indicate that none of the devices presently installed are unacceptable, marginally acceptable or showing significant change in delay time and performance.
3.
All spare end caps have been inspected with a 5X magnifying glass.
No cracks were found.
4.
The Administrative Procedure A-53.0, Preventive Maintenance Program, and the Maintenance Procedures M-32, Use of Circuit Breaker Multi-Amp Test Unit, and M-32.1, DB-25, DB-50 and DB-75 Circuit Breaker Main-tenance and Overcurrent Trip Device Test and/or Replacement, have been g9 reviewed.
To assure that all safety-related circuit breakers are tested at least each refueling outage to confirm overcurrent time delay protection, a change to the A-53.0, Preventive Maintenance Program, willbe made to goososo 6 c /
<<ROCHESTER GAS AND ELECTRIC DATE June 25, 1979 Mr. Boyce H. Grier, Director SHEET NO.
2 incorporate multiamp testing of all safeguards breakers during each shutdown.
Thus far we have maintained the practice of such yearly testing with the exception of alternating years testing of the motor control center 1C and 1D supply breakers to minimize the number of safeguards bus outages during a refueling outage.
Very truly yours, L. D. Wh e, Jr.