ML20077M828
| ML20077M828 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/12/1983 |
| From: | Oprea G HOUSTON LIGHTING & POWER CO. |
| To: | Jay Collins NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-SSINS-6820 IEB-80-19, ST-HL-AE-988, NUDOCS 8309120425 | |
| Download: ML20077M828 (3) | |
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The Light NE f Ilouston 1.ighting & l'ower It o.11ox 1700 liouston,1cxas s,ool (713) 228 9211 August 12 1983 ST-HL-AE588 File Number: G3.3
$h &[N Mr. John T. Collins Regional Administrator, Region IV AU6 I 6 @
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ij Nuclear Regulatory Commission
,~
b 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76011
Dear Mr. Collins:
South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Revised Response to IE Bulletin 80-19 By letter dated August 26, 1980, Houston Lighting & Power Company (HL&P) submitted a response to NRC IE Bulletin 80-19.
The response indicated that a review of the South Texas Project (STP) Reacter Protection System (RPS) had been performed to determine if C. P. Clare Model HG2X-1011 mercury-wetted relays were used in the STP RPS and that no mercury-wetted relays of any type were used in the STP RPS.
HL&P has determined that our original August 26, 1980 response was not entirely correct. Mercury-wetted relays are being used in the Westinghouse (W) 7300 Process Control and Protection System. These relays are hermetically sealed and used for temperature channel test inputs from resistor thermal devices.
These relays are not used in matrix logic applications or in scram circuits as described in the subject Bulletin.
HL&P has recently reported a deficiency pursuant to 10CFR50.55(e) on July 1, 1983 concerning the mercury relays in the W 7300 Process Control Panel Protection System. During seismic testing oT the temperature channel test card, contact bounce was experienced in the mercury relay utilized on this card. This intermittent contact bounce will result in signal saturation of the downstream RTD Amplifier (NRA) card in the T(hot) and T(cold) circuits of the W 7300 Process Control and Protection System.
Saturation of the NRA card in non-filtered applications (as is the case for STP) could delay initiation of the Overtemperature-Delta T and Overpower-Delta T trips. Such 8309120425 830812 PDR ADOCK 05000498 PDR a
I I
Houston Lighting & Power Company ST-HL-AE-988 File Number: G3.3 Page 2 saturation would only occur as a result of contact bounce induced by a seismic' event coincident with the demand for such a trip. The suspect relays will be replaced.
If you should have any questions concerning this item, please contact Mr. Michael E. Powell at (713) 877-3281.
Very truly yours, q?
,4,
.j rea, r.
Exectttive Vice President MEP/bjc-
Ilouston lighting & Power Company i
cc:
G. W. Oprea, Jr.
ST-HL-AE-988 J. H. Goldberg File Number: G3.3 J. G. Dewease Page 3 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 Bechhoefer, Esquire Central Power & Light Company Chairman, Atomic Safety & Licensing Board U. S. Nuclear Regulatory Commission P. O. Box 2121 Washington, D. C.
20555 Corpus Christi, Texas 78403 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, lexas 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