ML19351G561

Initial Deficiency Rept Re Tilting or Differential Settlement of Mechanical Electrical Auxiliary Bldg.Approx 11,143 Tons of Backfill Were Removed from Around Bldg & Replaced W/Concrete Placements to Correct Tilt

ML19351G561
Person / Time
Site:	South Texas
Issue date:	02/03/1981
From:	Oprea G HOUSTON LIGHTING & POWER CO.
To:	Seyrfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
References
10CFR-050.55E, 10CFR-50.55E, ST-HL-AE-616, NUDOCS 8102250222
Download: ML19351G561 (5)

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February 3, 1981 ST-HL-AE-616 SFN: C-0510 Mr. Karl Seyfrit Director, Region IV Nuclear Regulatory Commission 611 Ryan Pla::a Drive Suite 1000 Arlington, Texas 76012 South Texas Project Units 162 Docket Nos. STN 50-498, STN 50-499 Unit II MEAB Settlement

Dear Mr. Seyfrit:

' This confirms our conversation of February 2,1981, relating to the settlement of Unit II Mechanical Electrical Auxiliary Building (MEAB).

Tilting or differential settlement and curvature of the mat were anti-cipated and factored into the design. Although the design criteria was exceeded the corrective action taken has brought the tilt and curvature within tolerance and it is expected that conditions will continue to improve.

The maximum design tilt in the MEAB is defined in FSAR Section 2.5.4.11 and is specified as 0.5 inches tilt in the North-South direction. This differential settlement criteria is to be applied at the time of penetration connections or pipe installations for Category I piping. The North local curvature criteria is defined as 0.25 inches. The values f6r maximum design tilt and North local curvature were exceeded by 0.2 inches and 0.05 inches respectively.

As I discussed with you, the tilt and curvature experienced by the Unit II MEAB foundations mat resulted from the deviation from the planned construc-tion loading sequence. The major contributor to the situation was caused by our inability to place backfill around the North end of the building.

This was discussed with the Resident Inspector on April 11, 1980.

The corrective actions taken to correct this situation involved the removal O/7 of approximately 11,143 tons of backfill from around the South and Southeast end of the building and the scheduling of concrete placements such that the S North portion of the building will be loaded first.

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Houston Lighting & Power Company Mr. Karl Seyfrit ST-HL-AE-616 February 3, 1981 Page 2 These efforts to correct this situation have been very successful. The following are the results of the latest evaluation of the monitoring data.

NORTH LOCAL DATE OVERALL TILT CURVATURE 06/04/80 0.7 0.2 08/07/80 0.3 0.3 09/11/80 0.22 0.25 11/25/80 0.15 0.25 01/22/81 0.12 0.23 Monitoring of the settlement and curvature will continue and is currently being conducted on a bi-weekly basis.

If additional information is required, please advise.

D Very truly yours, G. W. Oprea, Jr.

Executive Vice President DGB/cmd i

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Houston Lighting & Power Company Mr. Karl Seyfrit ST-HL-AE-616 February 3, 1981 Page 3 cc: J. H. Goldberg D. G. Barker Howard Pyle R. L. Waldrop H. R. Dean D. R. Beeth J. D. Parsons G. B. Painter L. K. English A. J. Granger R. A. Frazar H. S. Phillips (NRC)

J. O. Read (Read-Poland, Inc.)

M. D. Schwarz (Baker &Botts)

R. Gordon Gooch (Baker & Botts)

J. R. Newman (Lowenstein, Newman, Reis & Axelrad)

Director, Office of Inspection & Enforcement Nuclear Regulatory Cannission Washington, D. C. 20555 I

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Housta Lighting & Powes Company Mr. Karl Seyfrit ST-HL-AE-616 February 3, 1981 Page 4 M. L. Borchelt Executive Vice President Central Power & Light Company P. O. Box 2121 Corpus Christi, Texas 78403 R. L. Range Central Power & Light Company P. O. Box 2121 Corpus Christi, Texas 78403 R. L. Hancock Director of Electrical Utilities City of Austin P. O. Box 1088 Austin, Texas 78767 T. H. Muehlenbeck City of Austin P. O. Box 1088 r Austin, Texas 78767 J. B. Poston Assistant General Manager of Operations City Public Service Board P. O. Box 1771 San Antonio, Texas 78296 A. vonRosenberg City Publ'ec Service Board P. O. Box 1771 San Antonio, Texas 78296 l

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Houston Lighting & Power Company Mr. Karl Seyfrit ST-HL-AE-616 February 3,1981 Page 5 Charles Bechoefer, Esquire Chairman, Atomic Safety & Licensing Board U. S. Nuclear Regulatory Commission Washington, D. C. 20555 Dr. James C. Lamb, III 313 Woodhaven Road Chapel Hill, North Carolina 27514 Dr. Emmeth A. Luebke Atomic Safety & Licensing Cannission U. S. Nuclear Regulatory Cannission Washington, D. C. 20555 Citizens for Equitable Utilities c/o Ms. Peggy Buchorn Route 1, Box 1684 Brazoria, Texas 77422 Pat Coy Citizens Concerned About Nuclear Power 5106 Casa Oro San Antonio, Texas 77422 Betty Wheeler Hoffman, Steeg & Wheeler 1008 S. Madison Amarillo, Texas Brian E. Berwick Assistant Attorney General for the State of Texas P. O. Box 12548 Capitol Station Austin, Texas 78711 Bernard M. Bordenick l

Hearing Attorney Office of the Executive Legal Director l

U. S. Nuclear Regulatory Commission Washington, D. C. 20555 l

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