ML20024E036
| ML20024E036 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/01/1983 |
| From: | Oprea G HOUSTON LIGHTING & POWER CO. |
| To: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-PT21-83-063-000 10CFR-50.55E, PT21-83-063-000, PT21-83-63, ST-HL-AE-981, NUDOCS 8308090083 | |
| Download: ML20024E036 (3) | |
Text
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ST-HL-AE-981 File Number: G12.151 n@@KMK) t l
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Mr. John T. Collins AUG I E
i Regional Administrator, Region IV Nuclear Regulatory Commission h
611 Ryan Plaza Drive, Suite 1000 u-Arlington, Texas 76011 J
Dear Mr. Collins:
South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Final Report Concerning the Westinghouse 7300 Process Control & Protection System On July 1,1983, pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) notified your office of an item concerning the Temperature Channel Test (NTC) card in the Westinghouse 7300 Process Control and Protection System. Attached is the Final Report which identifies the corrective actions to be implemented.
If you should have any questions concerning this item, please contact Mr. Michael E. Powell at (713)877-3281.
Very truly yours,
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Execu ive V1 e President MEP/bc Attachment 8308090003 830801 gDRADOCK05000 7g-37 li i k
Houston Lighting & Power Company cc:
G. W. Oprea, Jr.
ST-HL-AE-981 J. H. Goldberg File Number: G12.151 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)
A. Vietti 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 Comission 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, N. W.
P. O. Box 12548 Suite 506 Capitol Station Washington, 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 07-05-83
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Final Report Concerning The Westinghouse 7300 Process Control & Protection System I.
Summary Pursuantto10CFR21and10CFR50.55(e).. Westinghouse (W)hasnotified the NRC of a potential problem with the Temperature CEannel Test (NTC) card in the W 7300 Process Control and Protection System. The subject cards will be replaced.
II.
Description of the Deficiency On July 1, 1983, pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) tutified your office of an item concerning W supplied NTC card relays used in the 7300 Process Control and Protection System for the NRC, pursuant to both 10CFR2T and 10CFR50.55(e) ported this it the South Texas Project (STP). W has previously re, providing a list of potentially affected plants of which STP was one. During seismic testing of the NTC card, contact bounce was experienced in the mercury relay utilized on this card. This intermittent contact bounce could result in signal saturation of the downstream RTD Amplifier (NRA) card in the T(hot)~ and T(cold) circuits of the 7300 Process Control and Protection System.
Saturation of the NRA card in the non-filtered STP design application could delay initiation of Overtemperature-Delta T and Overpower-Delta T trips. Such saturation induced delay would only occur as a result of contact bounce induced by a seismic event coincident with the demand for such a trip.
W is developing and testing a replacement relay for the NTC cards.
III. Corrective Action A replacement relay is being developed and tested. Since the failure occurred during seismic testing, the replacement relay will be designed to respond appropriately. W Field Change Notices (FCN's) will be issued during 1984 for both units.
IV.
Recurrence Control A recurrence control program is not necessary.
V.
Safety Analysis Utilization of these cards may have resulted in delay of Overtempera-ture-Delta T and Overpower-Delta T trips. Since the plant safety analysis does not account for potentially delayed trips during the seismic event, an unanalyzed condition could result. Therefore, this deficiency is considered to be reportable pursuant to 10CFR50.55(e).
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