ML13310B401
| ML13310B401 | |
| Person / Time | |
|---|---|
| Site: | San Onofre  |
| Issue date: | 04/27/1984 |
| From: | Medford M SOUTHERN CALIFORNIA EDISON CO. |
| To: | Crutchfield D Office of Nuclear Reactor Regulation |
| References | |
| GL-83-28, NUDOCS 8405140428 | |
| Download: ML13310B401 (2) | |
Text
Southern California Edison Company P. 0. BOX 800 2244 WALNUT GROVE AVENUE ROSEMEAD, CALIFORNIA 91770 M.O. MEDFORD
'7lOATELEPHONE MANAGER, NUCLEAR LICENSING April 27, (213) 572-1749 Director, Office of Nuclear Reactor Regulation Attention: D. M. Crutchfield, Chief Operating Reactors Branch No. 5 Division of Licensing U. S. Nuclear Regulatory Commission Washington, D.C.
20555 Gentlemen:
Subject:
Docket No. 50-206 Westinghouse DB-50 Reactor Trip Breaker Maintenance San Onofre Nuclear Generating Station Unit 1
Reference:
November 28, 1983 letter from M. 0. Medford, SCE, to D. M. Crutchfield, NRC, concerning Generic Letter 83-28:
Required Actions Based on Generic Implications of Salem ATWS Events Per a commitment made in the reference, this letter forwards the status of our efforts to incorporate the latest Westinghouse Owners Group recommendations into the SONGS 1 reactor trip breaker maintenance program.
The most recent Westinghouse Technical Bulletin, Addendum 1 to NSD-TB-83-02, Rev. 1, transmitted an initial lubrication kit which conforms to the revised lubrication recommendations for UVTA's in DB-50 reactor trip applications. In addition to this kit, a document entitled "DB-50 Reactor Trip Switchgear-Maintenance Program" was also transmitted, which provides a complete compilation of Westinghouse reactor trip breaker maintenance recommendations. Per our commitment, discrepancies between our current maintenance program and the most recent Westinghouse Owners Group recommended program have been identified.
These discrepancies are primarily minor wording differences and will not involve significant changes to the present program.
These discrepancies will be corrected by July 15, 1984. At that time, our DB-50 Reactor Trip Breaker Maintenance program will be in full conformance with the Westinghouse Owners Group maintenance recommendations.
As an additional item, also transmitted by Addendum 1 to NSD-TB-83-02, Rev. 1, Westinghouse recommended a replacement life cycle for UVTA's. Based on Industry Standards and reliability testing completed to date, it is Westinghouse's recommendation that UVTA's be replaced after 1250 cycles. Based on the current maintenance and testing programs at SONGS 1, and accounting for planned and un-planned reactor trips, we conservatively estimate the UVTA's are cycled not more than 25 times per year. This frequency corresponds to a 50 yearU VTA life cycle at SONGS 1. Since the 8405140428 840427 PDR ADOCK 05000206 P
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Mr. D.
April 27, 1984 present UVTA's were installed in 1972, the projected replacement date, due to cumulative UVTA cycles, would be the year 2022. Because this date is well beyond the expected life of SONGS 1, replacement of the UVTA's will be dictated by factors other than aging. Therefore, it is not necessary to incorporate into the breaker maintenance and testing program a provision for replacement of the UVTA's at a specified future date due to UVTA cycling. For the SONGS 1 breaker maintenance and testing program, omission of this provision does not constitute an exception to the Westinghouse recommended program.
Please contact me if you have any questions or require additional information.
Subscribed on this 247"A day of 1984.
Respectfully submitted, SOUTHERN CALIFORNIA EDISON COMPANY By:
M. 0. Medford Manager, Nuclear Licensing Subs ribed and sworn to before me th)s 7-17 d ay o f 5Fs,2
/fy.
OFFICIAL SEAL BETTY A. McBAY NOTARY PUBLIC. CALIFORNIA
&cz-7w, wn Ag. 24, 1987 N6tary P blic in and for he County of Los Angeles, State of California cc:
Document Control Desk (10 copies)
Eileen McKenna, NRC Project Manager