ML20009E419
| ML20009E419 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 07/08/1981 |
| From: | Oprea G HOUSTON LIGHTING & POWER CO. |
| To: | Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| 10CFR-050.55E, 10CFR-50.55E, ST-HL-AE-685, NUDOCS 8107280183 | |
| Download: ML20009E419 (3) | |
Text
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COIIIhEf elouston 1.ighiing & l'ower itO. Iha 1700 Ilouston 'Ieus <,001 (713) 22M211 qs(\\
t July 8, 1981 i
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Mr. Karl Seyf rit S'
Director, Region IV
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,s Nuclear Regulatory Commission b
j f[V 611 Ryan Plaza Drive, Suite 1000 trlington, Texas 76012
Dear Mr. Seyfrit:
South Texas Project Units 1 & 2 Docket Nos. STN 50-498, 50-499 Final Report Concerning Reactor Cavity Ventilation Design Please find attached our final report regarding reactor cavity ventilation design which Houston Lighting & Power Company verbally reported to your office on October 17, 1980 ae. being potentially reportable pursuant to 10CFR50.55(e).
If there are any questions, please contact Mr. Michael E. Powell at (713) 676-8592.
Very truly yours, G. W. Oorea, Jr.
Executive Vice President MEP/flj Attachment Ih s
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B107280183 810708 DR ADOCK 05000498 PDR
L llouston 1.ighting & Pimer Company cc:
J. H. Goldberg July 8, 1981 J. G. Dewease ST-Hu-AE-685 D. G. Barker SFN:
V-0530 C. G. Robertson Page 2 Howard Pyle R. L. Waldrop H. R. Dean D. R. Beeth J. D. Parsons J. W. Willians J. W. Briskin J. E. Geiger STP RMS H. S. Phillips (NRC)
J. O. Read (Read-Poland,Inc.)
M. D. Schwarz (Baker & Botts)
R. Gordon Gooch (Baker & Botts)
J. R. Newnan (Lowenstein, Newman, Reis, & Axelrad)
Director, Office of Inspection & Enforccaent Nuclear Regulatory Conmission Washington, D. C. 20555 M. L. Borchelt/R. L. Range Charles Bechhoefer, Esquire Central Power & Light Company Chairman, Atomic Safety & Licensing Board P. O. Box 2121 U. S. Nuclear R39ulatory Connission Corpus Christi, Texas 78403 Washington, D. C.
20555 R. L. Hancock/T. H. Muehlenbeck Dr. James C. Lamb, III aity of Austin 313 Woodhaven Road
- o. O. Box 1088 Chapel Hill, North Carolina 27514 Austin, Texas 78767 J. B. Poston/A. voqRosenberg Mr. Ernest E. Hill City Public Service Board Lawrence Livermore Laboratory P. O. Box 1771 University of California San Antonio, Tevas 78296 P. O. Box 808, L-123 Livermore, California 94550 Brian E. Berwick, Esquire William S. Jordan, III Assistant Attorney for the State of Texas Harmon & Weiss P. O. Box 12548 1725 I Street, N. W.
Capitol Station Suite 506 Austin, Texas 78711 Washington, D. C.
20006 l
l 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 j
1 Jay Gutierrez, Esquire l
Hearing Attorney Office of the Executive Legal Director U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Revision Date 7 81 u
e FINAL REPORT REACTOR CAVITY VENTILATION DESIGN July 8, 1981 DESCRIPTION OF THE INCIDENT On October 17, 1980, pursuant to 10CFR50.55(e), Houston Lighting &
Power Company notified your office of an item concerning the reactor cavity ventilation design for the South Texas Project Units 1 and 2.
The design criteria requires that ventilation be provided to the reactor cavity, primary shield wall penetrations, and inspection toroid volumes sufficient to maintain primary shield wall concrete temperatures within specified limits during normal plant operation. An analysis had indicated that the temperature of the primary shield wall concrete in the penetration and along the face exposed to the reactor vessel would exceed the specified limits. Based on this analysis the concern was identified to the NRC.
CORRECTIVE ACTION Since the issuance of our interim reports, a new analysis has been completed that demonstrates that the design as released for construction is in fact adequate.
Thus, no corrective action is necessary.
SAFETY ANALYSIS An evaluation of the reactor cavity thermal-hydraulics has been performed. As a result of this evaluation, it is concluded that the i
assumptions, which formed the basis for the original concern, were overly conservative. A new analysis was performed and the design as released for construction is in fact adequate.
For portions of the design (i.e. seal plate) which were still preliminary and not released for construction, changes were recommended to HL&P to enhance its performance.
HL&P has accepted the recommended changes for implementa-tion.
This review identified a failure mode in addition to those discussed in the FSAR.
The failure mode involves loss of HVAC in the cavity area during normal operation due to inadvertent damper operation in the subject area. Thus, additional instrumentation will be added to i
the plant design in order to alert the plant operator of this failure mode. The evaluation shows that upon loss of HVAC, temperature in the cavity area will not exceed specified limits within the first thirty (30) minutes of the loss. This provides ample time for operator action.
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