ML20076C565
| ML20076C565 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/15/1983 |
| From: | Oprea G HOUSTON LIGHTING & POWER CO. |
| To: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, ST-HL-AE-989, NUDOCS 8308230083 | |
| Download: ML20076C565 (3) | |
Text
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The Light m m P u Y iie""" i.ix 'i"x & is << i o.iiex >>oo ii e'
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August 15, 1983 ST-HL-AE-989 File Number: G12.153 p @"!;. y' ' m' i
Mr. John T. Collins r
Regional Administrator, Region IV i
.w 1.n Nuclear Regulatory Commission 611 Ryan Plaza Drive, Suite 1000
- d;I fijG 181993 Arlington, Texas 76011 h1[
! \\ 1.-.-
Dear Mr. Collins:
South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Final Report Concerning Instrumentation Associated with the Essential Cooling Water Pumps On July 18, 1983, pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) notified your office of an item concerning instrumentation associated with the Essential Cooling Water (ECW) System pumps. 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,
,/
Te%J.
Exe ' tive H e President MEP/mg Attachment 8308230083 830815 PDR ADOCK 05000498 S
//
o Ilous:on I.ighting & Power Company August 15, 1983 cc:
G. W. Oprea, Jr.
ST-HL-AE-989 J. H. Goldberg File Number: G12.153 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 Commission Washington, D. C. 20555 G. W. Muench/R. L. Range Charles Bethhoefer, 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
August 15, 1983 Attachment ST-HL-AE-989 l
South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Final Report Concerning Instrumentation Associated with the Essential Cooling Water Pumps I.
Summary The potential exists for a common mode failure to trip all of the Essential Cooling Water (ECW) System pumps. The ECW pumps cannot be re-started unless a Safety Injection (SI) signal is initiated. This item will be corrected by eliminating the potential for common mode failure.
i II.
Description of the Deficiency On July 18, 1983 pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) notified your office of an item concerning instrumentation associated with the ECW system pumps. The potential exists that under a loss of offsite power or loss of instrument air, this will cause the level switches in each ECW pump cubicle well to generate a false low water level signal.
This signal, in turn, will trip all of the ECW pumps. The ECW pumps cannot be re-started unless a SI signal is initiated. This is considered to represent a common mode failure.
The primary function of the level instrumentation is for pump protection and the level instrumentation is nonsafety-related.
III. Corrective Action The corrective action will be'to delete the automatic pump trip function for the low-level ECW pump cubicle well instrumentation. Annunciation in the control room will still exist.
IV.
Recurrence Control This design was a previous Brown & Root, Inc. (B&R) design. Bechtel uses established procedures for design interface control, design verification and the requirement for failure modes and effects analyses of safety-related systems.
Implementation of these procedures will provide the appropriate recurrence control.
V.
Safety Analysis The potential for a common mode failure is considered to represent a challenge to the ECW system such that it could adversely affect the safe operation of the plant.
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