ML20065S470
| ML20065S470 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 10/28/1982 |
| 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-896, NUDOCS 8211010248 | |
| Download: ML20065S470 (4) | |
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1 The Light COmpaRY Ilou5 ton Lighting & Power P.O. Box 1700 liouston, Texas 77001 (713)228-9211 October 27, 1982 ST-HL-AE-896 File Number: G12.67 SFN: V-0530
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Mr. John T. Collins
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Regional Administrator, Region IV
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Nuclear Regulatory Commission
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611 Ryan Plaza Dr., Suite 1000 Arlington, Texas 76012
Dear Mr. Collins:
South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Final Report Concerning Environmental Qualification of Electrical Equipment Associated with the Auxiliary Feedwater Pumps On August 25, 1980, pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) notified your office of an item concerning environmental qualification of electrical equipment associated with the auxiliary feedwater pumps. Attached is the Final Report concerning this item.
If you should have any questions concerning this matter, please contact Mr. Michael E. Powell at (713) 877-3281.
Very tr ly yours, a
Exec 'ive V' e President f
MEP/mg Attachment 1
8211010248 821028 PDR ADOCK 05000498 S
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I Ilouston Lighting & Power Company October 27, 1982 cc:
G. W. Oprea, Jr.
Si-HL-AE-896 J. H.'Goldberg File Number: G12.67 1
J. G. Dewease Page 2 J. D. Parsons D. G. Barker
]
M. R. Wisenburg l
R. A. Frazar l
J. W. Williams R. J. Maroni J. E. Geiger H.-A. Walker S. M. Dew J. T. Collins (NRC)
D. E. Sells (NRC) j W. M. Hill, Jr.
(NRC)
M. D. Schwarz (Baker & Botts) a R. Gordon Gooch (Baker & Botts)
J. R. Newman-(Lowenstein, Newman, Reis, & Axelrad)
Director, Office of Inspection & Enforcement Nuclear Regulatory Commission Washington, D. C. 20555 G. W. Muench/R. L. Range Charles Bechhoefer, Esquire l
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 i
i Brian E. Berwick, Esquire William S. Jordan, III Assistant Attorney General Harmon & Weiss i
for the State of Texas 1725 I Street, N. W.
P. O. Box 12548 Suite 506 Capitol Station Washington, D. C.
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 Jay Gutierrez, Esquire Hearing Attorney Office of the Executive Legal Director U. S. Nuclear Regulatory Commission Washington, D. C.
20555 Revision Date 10-18-82
Attachment 1
Final Report Concerning Environmental Qualification of Electrical Equipment Associated with the Auxiliary Feedwater Pumps I.
SUMMARY
As the result of an environmental qualification design review by Brown &
Root, Inc. (B&R), electrical equipment (including pump motors) associated with the auxiliary feedwater (AFW) pumps was identified to be qualified to a temperature which was below expected accident conditions.
This item was later expanded to include the backdraft dampers in the Isolation Valve Cubicle (IVC) Heating Ventilation and Air Conditioning (HVAC) system. These matters are associated closely with a recently reported deficiency concerning the design loadings for the IVC walls. The IVC is currently being redesigned and the design of the AFW pump cubicles is included in this redesign effort.
II.
DESCRIPTION OF THE INCIDENT On August 25, 1980, pursuant to 10CFR50.55(e), Houston Lighting & Power Company (HL&P) notified your office of an item concerning environmental qualification of electrical equipment associated with the auxiliary feedwater pumps. As a result of an environmental qualification design review, the electrical equipment associated with AFW pumps was identified to be qualified to a temperature which is below accident conditions resulting from a High Energy Line Break (HELB) within the IVC. The affected equipment is located at elevation +10' of the IVC structure on each unit. This condition was documented by B&R on an Engineering Design Deficiency (EDD),80-310. A detailed description of this item was provided in our First Interim Report on September 24, 1980.
On April 22, 1982, HL&P expanded the scope of this deficiency to include the backdraft dampers in the IVC-HVAC system. The subject backdraft dampers were not specified to withstand the pressure transient associated with an HELB inside the IVC. Failure of these dampers could allow the IVC-HVAC system to be disabled.
III. CORRECTIVE ACTION The design of the AFW pump cubicles is being considered in a complete review and redesign of the IVC.
In this redesign effort, sufficient isolation will be provided between AFW pump cubicles to enable the environment to be maintained at an acceptable level for the AFW trains not directly affected by the postulated HELB.
Complete separation will be provided between train-oriented HVAC systems. The redesign and restart of 4
construction, as currently scheduled, is shown on the Milestone Summary Schedules (line number 10) provided under separate cover on September 20, 1982.
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Attachment 1
Page 2 l
IV. RECURRENCE CONTROL The fundamental plant design philosophy at STP dictates that safety-related systems be redundant, independent and provided with adequate isolation to preclude unacceptable systems interaction. STP Systems Interaction Design Guide is being developed and will include guidance for separation and consideration of fire, flooding, seismic events, missiles, single failure and pipe break effects.
V.
SAFETY ANALYSIS Without a redesign of the IVC, an HELB in one AFW pump cubicle could have resulted in environmental conditions in adjacent cubicles which exceed the conditions for which the pumps were qualified. This could result in a loss of AFW in the unaffected trains. This is considered to represent a significant safety hazard.
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