ML20071M354
| ML20071M354 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 05/26/1983 |
| From: | Clayton F ALABAMA POWER CO. |
| To: | Varga S Office of Nuclear Reactor Regulation |
| References | |
| NUDOCS 8305310201 | |
| Download: ML20071M354 (2) | |
Text
O, MWWg Adeon Alibims Power Corppany 600 Nor tn 18th Street Post Office Box 2641 Birmingham, Alabama 35291 Telephone 205 783-6081 F. L Clayton, Jr.
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the southem electric system May 26, 1983 Docket Nos. 50-348 50-364 Director, Nuclear Reactor Regulation U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Attention:
Mr. S. A. Varga Joseph M. Farley Nuclear Plant - Units 1 and 2 Adequacy of Current Farley DS-416 Reactor Trip Breaker Gentlemen:
Alabama Power Company has described the action taken regarding recent problems with the DS-416 breakers in letters dated March 4,1983, March 25, 1983 and May 10, 1983.
To resolve problems identified in Westinghouse letters dated March 31, 1983 (UV trip attachment dimen-sional variations) and April 21,1983 (shaf t retaining ring groove variations), Alabama Power Company replaced the UV trip attachments with devices which were modified to specific dimensional clearances and with widened grooves for shaft retaining rings.
Dimensional clearances were verified af ter the new UV trip attachments were installed.
Following the. installation of the new UV trip attachments at the Farley Nuclear Plant and during a 25 cycle bench test checkout procedure of the reactor trip breakers, one of the trip breakers failed to trip on the tenth test.
It was determined that the new UV trip attachment did not properly interface with the breaker tripping mechanism (i.e.,
in-adequate overtravel) to ensure reliable operation.
Westinghouse devel-oped criteria and a field test procedure for determining acceptable minimal overtravel to assure reliable operation.
The UV trip attachment on the breaker discussed above was replaced and proper overtravel was ve ri fi ed.
Adequate overtravel of all other UV trip attachments on the Farley Nuclear Plant reactor trip breakers and bypass breakers was verified.
In summary, the Farley Nuclear Plant DS-416 breaker configuration has been modified based on identified problems, appropriate breaker dimensional alignment has been verified, extensive bench testing has been performed to ensure proper breaker operation, and in-place breaker testing has continued to demonstrate satisfactory results.
Alabama s
Power Company therefore concludes that the safe operation of Farley Nuclear Plant - Units 1 and 2 is not adversely impacted by the DS-416 reactor trip breakers.
8305310201 830526
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m Mr. S. A. Va rga May 26, 1983 U. S. Nuclear Regulatory Commission Page 2 If there are any question, please advise.
You rs ve ry t ruly,
__0 f L. Clayton, t r.
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Mr. R. A. Thomas Mr. G. F. Trowbridge Mr. J. P. O'Reilly Mr. E. A. Reeves Mr. W. H. B radf ord D r. I. L. Myers l
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