ML20076D635
| ML20076D635 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 05/18/1983 |
| From: | Oprea G HOUSTON LIGHTING & POWER CO. |
| To: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-PT21-83 10CFR-050.55E, ST-HL-AE-959, NUDOCS 8305230525 | |
| Download: ML20076D635 (4) | |
Text
s The Light Company ii.,,,si,,,, u i,o,ix & i>,,m<.
x m ii.,x i 7on i i.,,,si,,,,. i.<.m.,77oni oi33 m..,2ii May 18, 1983 ST-HL-AE-959 File Number: G12.145
@@ {ggym Mr. John T. Collins Regional Administrator, Region IV E
Nuclear Regulatory Commission l'
l 611 Ryan Plaza Dr., Suite 1000 NAY l 81983 Arlington, Texas 76012 a
g Dear Mr. Collins-South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Final Report Concerning the Westinghouse Reactor Trip Switchgear On April 22, 1983, pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) notified your office of an item concerning the Westinghouse Reactor Trip Switchgear. Attached is the Final Report which identifies the corrective actions to be implemented.
If you should have any questions concerning this item, please contact Michael E. Powell at (713) 877-3281.
Very truly yours,
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6 Executive Vice President MAM/kr 1
Attachment 1
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8305230525~830518 g[
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llouston Lighting & Power Companv May 18 1983 cc:
G. W. Oprea, Jr.
ST-HLdE-959 J. H. Goldberg File Number: G12.145 J. G. Dewease Page 2 J. D. Parsons D. G. Barker M. R. Wisenburg R. A. Frazar J. W. Williams R. J. Maroni J. E. Geiger H. A. Walker S. M. Dew J. T. Collins (NRC)
H. E. Schierling (NRC)
W. M. Hill, Jr.
(NRC)
M. D. Schwarz Baker & Botts)
R. Gordon Gooch Baker & Botts)
J. R. Newman Lowenstein, Newman, Reis, & Axelrad)
STP RMS Director, Office of Inspection & Enforcement Nuclear Regulatory Commission Washington, D. C. 20555 G. W. Muench/R. L. Range Charles Bechhoefer, Esquire Central Power & Light Company Chairman, Atomic Safety & Licensing Board P. O. Box 2121 U. S. Nuclear Regulatory Commission Corpus Christi, Texas 78403 Washington, D. C.
20555 H. L. Peterson/G. Pokorny Dr. James C. Lamb, III City of Austin 313 Woodhaven Road P. O. Box 1088 Chapel Hill, North Carolina 27514 Austin, Texas 78767 J. B. Poston/A. vonRosenberg Mr. Ernest E. Hill City Public Service Board Lawrence Livermore Laboratory P. O. Box 1771 University of California San Antonio, Texas 78296 P. O. Box 808, L-46 Livermore, California 94550 Brian E. Berwick, Esquire William S. Jordan, III Assistant Attorney General Harmon & Weiss for the State of Texas 1725 I Street, h. W.
P. O. Box 12548 Suite 506 Capitol Station W6shington, D. C.
20006 Austin, Texas 78711 Lanny Sinkin Citizens for Equitable Utilities, Inc.
Citizens Concerned About Nuclear Power c/o Ms. Peggy Buchorn 5106 Casa Oro Route 1, Box 1684
-San Antonio, Texas 78233 Brazoria, Texas 77422 Robert G. Perlis, Esquire Hearing Attorney Office of the Executive Legal Director U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Revision Date 04-29-83
Final Report Concerning the Westinghouse Reactor Trip Switchgear I.
Summary Westinghouse Electric Corporation advised Houston Lighting & Power Company (HL&P) on April 21, 1983 that they had determined that a deficiency existed in the design of the reactor trip switchgear undervoltage attachments. Westinghouse further stated they had informed the Nuclear Regulatory Commission that this condition existed in equipment delivered to the South Texas Project, among others, and had reported this condition pursuant to 10CFR21.
The undervoltage attachments on the STP reactor trip switchgear will be replaced.
II. Description of the Deficiency Westinghouse has identified a manufacturing discrepancy relative to undervoltage attachments on DS-416 reactor trip switchgear supplied for their Nuclear Steam Supply Systems. The Westinghouse evaluation of the discrepancy concluded that deviations from recommended clearances could increase the potential for misoperation of the undervoltage attachment.
Additionally, Westinghouse identified a deficiency in design related to the undersizing of grooves in the pivot shafts for the undervoltage attachments. Therefore, retaining rings which maintain the pivot shaft in proper position may not seat properly. As a consequence, the pivot shafts may become misaligned with the guide holes in the frame of the undervoltage attachment and not allow the attachment to function properly on demand.
(See attached figure).
III. Corrective Action Westinghouse has advised HL&P that it intends to replace the existing undervoltage attachments for STP with newly designed and manJfactured components. Bechtel Home Office Engineering has instructed the field to initiate a Nonconformance Report to identify the deficient hardware and prevent it from being placed in service prior to the completion of required modifications. The switchgear undervoltage attachments will be replaced on a schedule commensurate with the project schedule.
IV. Recurrence Control In correspondence with HL&P, Westinghouse indicated their manufacturing drawings and quality control procedures will be modified to assure that critical design dimensions are maintained during manufacture.
V.
Safety Analysis Westinghouse has indicated that this condition could have potentially prevented the reactor trip switchgear from opening on automatic demand from the reactor protection system. This is considered to represent a safety hazard requiring the corrective action reported above to preclude unacceptable consequences. Therefore, HL&P considers this condition to be reportable pursuant to 10CFR50.55(e) and, based upon information from Westinghouse, also reportable pursuant to 10CFR21.
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