ML20127A120
| ML20127A120 | |
| Person / Time | |
|---|---|
| Site: | Comanche Peak  |
| Issue date: | 01/08/1993 |
| From: | William Cahill, Walker R TEXAS UTILITIES ELECTRIC CO. (TU ELECTRIC) |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| CP-92-004, CP-92-4, TXX-93014, NUDOCS 9301110189 | |
| Download: ML20127A120 (2) | |
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File # 10110 2
- 908.3 Ref.
TUG E(lHW:
January 8, 1993
% ihm J. Cohlit, Jr.
thusy. % e bruJent U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555
SUBJECT:
COMANCHE PEAK STEAM ELECTRIC STA110N (CPSES)
DOCKET N05. 50-445 AND 50-446 DEVIA110NS IN ELGAR INVERTERS SDAR: CP-92-004 (SUPPLEMENTAL REPORT)
Gentlemen:
On May 13, 1992, via f acsimile, TV Electric notified the NRC of numerous manuf acturing deficiencies in printed circuit boards (PCBs) for the Unit 2 Class lE electric power inverters.
Subsequently, TV Electric notified the NRC pursuant to 10CFR50.55(e) of a breakdown in the manufacturer's Quality Assurance (QA) program for the subject PCBs (TXX-92273 dated June 26,1992).
1XX-92273 described the specific deficiencies found in the Unit 2 PCBs, indicated that the deficiencies were not applicable to Unit I and stated that a review would be conducted of the manufacturer's report for preventing these deficiencies.
This voluntary letter is submitted to provide the results of this review and identify additional actions being taken by TV Electric.
10 Electric has reviewed the manuf acturer's f ailure Analysis Report for the specific deficiencies discussed in TXX-92273.
The analysis of these deficiencies was considered adequate, however, TU Electric could not cnnclude from the report that comprehensive actions necessary to resolve QA program weaknesses would be taken.
In addition, more PCB deficiencies similar to those previously described have been documented since submitcal of TXX-92273.
The following actions have been or are being implemented to resolve these concerns.
1.
Baseline data has been established for each PCB by identifying the latest revision (s) supplied or recommended by the manufacturer or known to be acceptable based on testing and operating history at CPSES.
2.
The approved revision (s) identified in the baseline data have been incorporated into the Purchasing and Materials Management System (PMMS).
Future purchase orders for replacement PCBs will identify these revisions.
In addition, safety related purchase orders will be subject to source inspections for configuration, workmanship and witnessing of 9301110189 930108 PDR ADOCK 05000446 S
PDR 400 N. Otive street LB. 81 Dalles,1exa 13201
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TXX-93014 Page 2 of 2 I
factory testing. These source inspections will continue as an interim 1
measure until confidence in the manufacturer's QA program is established.
3.
Future revisions to PCBs by the manufacturer will be reviewed by Engineering to assess the impact of those changes on proper functioning 4
of the PCBs.
These reviews will be conducted prior to use of revised PCBs at CPSES.
In addition. Engineering will review factory test procedures used to test the PCBs as discussed in item 2. above.
4 PCBs currently in the warehouse that were not subjected to the controls described above will be returned to the manufacturer.
10 Electric believes that the actions described above will naintain the quality of the subject Class lE inverters being utilized at'CPSES.
Sincerely, William J. Cahill, Jr.
I By:
M Roger D. Walker Manager of Regulatory Affairs for NE0 JAA/tg c-Mr. J. L. Milhoan, Region IV Resident inspectors, CPSES (3)
Mr. T. A Bergman, NRR Hr. B. E. Holian, NRR
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