ML20081F333
| ML20081F333 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 05/31/1991 |
| From: | William Cahill TEXAS UTILITIES CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CP-84-04, CP-84-4, TXX-91191, NUDOCS 9106070320 | |
| Download: ML20081F333 (2) | |
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Log 8 TXX 91191 file # 10110 10010 71/D fr7Rlt.
910.3 Ref. # 10CFR50.55(e) un.m u.i.ma,.
May 31, 1991 o..
. n, in.a..a U. S. Nuc1 car Regulatory Commission Attn: Document Control Desk Washington, D. C.
20555
SUBJECT:
COMANCllE PEAK STEAM ELECTRIC STATION (CPSES)
DOCKET NOS. 50 445 AND 50 446 TERRORE50NANT TRANSFORMERS SDAR CP-84 04:
SUPPLEMEN1AL REPORT Gentlemen:
On February 13, 1984, TV Electric reported, via letter from R. J. Gary to E.
H. Johnson logged TXX-4109, a deficiency involving grounded secondary windings on ferroresonant transformers in Westinghouse safety-related inverters. At the time of the report, there were nine spare transformers in the warehouse and four installed in each Unit, for a total of seventeen Class lE transformers on site. The corrective action commited to in the letter was to return the transformers to Westinghouse for repair by the manufacturer (General Electric).
On April 4, 1990, TV Electric submitted Licensee Event Report 90 002, by letter from W. J. Cahill, Jr. to NRC logged TXX-90127.
The report described a reactor trip and a Source Range flux Doubling signal which resulted from an inverter fuse failure. During investigation of the inverter fuse failure IV Electric determined that only twelve of the transformers on site in 1984 had been returned to Westinghouse as committed. Three of the five transformers which were not returned are currently installed in Unit 1.
Two of these have been successfully high pot tested in accordance with the test procedure detailed in Wr stinghouse Technical Bulletin NSD TB 84-11.
The third transformer has been operating since approximately August 1989, and meets the six month operating time specified in NSD TB 84-ll.
The two remaining spare transformers have also been successfully high-pot tested.
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TXX 91191 Page 2 of 2 This oversight occurred due to the existence of two material management organizations, the Operation Material Group and the Construction Material Group, which served different functions.
The five transformers that were not returned to the manufacturer were in the custody of 0)eration Material Group.
Since the two material groups operated differently, 11e requirement to return the defective transformers was not adequately transmitted to the Operation Material Group.
Presently, the Material Management Organization provides an integrated approach and serves both operation and construction which will preclude recurrence of this oversight.
TV Clectric concludes that the failure to return these transformers as commited and their subsequent use has no safety significance and is not a separately reportable deficiency.
Sincerely,
/.
William J. Cahill, Jr.
OB/bm c - Mr. R. D. Martin, Region IV Hr. M. l.. fields NRR Resident inspectors, CPSES (2)
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