ML20004D424

Responds to NRC Re Violations Noted in IE Insp Repts 50-498/79-19 & 50-499/79-19.Corrective Actions:Brown & Root Field Engineering Established Baseline Azimuths from Existing Controls

ML20004D424
Person / Time
Site:	South Texas
Issue date:	05/08/1981
From:	Oprea G HOUSTON LIGHTING & POWER CO.
To:	Seyfrit K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
Shared Package
ML20004D421	List: ML20004D420 ML20004D424
References
ST-HL-AE-667, NUDOCS 8106090381
Download: ML20004D424 (5)

Text

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.g The Light COMMY souston tigating & eo-er eo. sox tvoo nouston. Texas 77ooi <7is)ees-92it May 8, 1981 ST-HL-AE-667

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SFN: C-0560 Mr. Karl Seyfrit Director Region IV Nuclear dequlatory Commission 611 Ryan Plaza Drive, Suite 1000 Arlington, Texas 76012

Dear Mr. Seyfrit:

South Texas Project Units 1 & 2 Occket Nos. STN 50 498, STN 50 499 Metnod for Verifying the Location of the Dome Tendon Sheathina Inis letter is written in resoonse to the request in your letter of Acril 16,1981 that we inform you of :ne method for verifying the location of tne done tendon sneathing within specified radial tolerance.

During a meeting held at tne STP site on Aoril 9,1981 it became aooarent that some concerns existed as to how the location of the done tendon sneathing would be verified. The following methodology for verifyina the location of the dome tendon sneathing has been developed with Houston Lignting % Power Engineering concurrence:

(1) Brown & Root Field Engineering established baseline azimuths from existing control.

(2) Using the baseline azimuths already established, survey caselines are installed using the caseline azinuths as a means of reference.

These baselines range in distance from 1,000 feet to 1,400 feet from centerline of containment.

(See Attacnment 1)

(3) After tne survey baselines nave been installed, field Engineerine will use the h distance (distance from the baseline to :ne sheatning centerline) given on Prescon drawings to install oo nts alorn the survey baseline wnicn recresents the theoretical centerline of eacn sneathing.

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(4) Following tne installation of these tneoretical centerlines, Field Engineerino will align and cnecx installed sheathinq.

In order to acnieve this crocess, a Wild T-2 theodolite will be set uo on each 8106 0 9 0.3%l

Houston Lighting & Power Company May 8, 1981 ST-HL-AE-667 SFN: C-0560 Page 2 theoretical centerline.

The instrument man will turn 900 from an established backsight and out a survey mark on each sheatning corresponding to the theoretical centerline.

In order to assure his accuracy, the instrument man will again turn the 900 angle, making sure that he returns to the same location as the first mark. Should he fail to match the first location, this orocess is repeated until the same location is assured. A point will be established on the sheathing and on the form.

(5) After theoretical centerline has been established nn the form and the sneathing, a stringline will be pulled between these two coints. While this strinaline is in olace a temolate marked with gradations is olaced next to the stringline so that the gradation marks parallel to the stringline shows the. distance the in olace sheatning is from

neoretical centerline.

If the dist s a exceeds the 3/4" tolerance, the sneatning will be moved and the ort,ess repeated.

(See Attachment 2)

(6) Once the alignment criteria has been met, the sheathing is checked witn respect to the liner. The shortest distance between the sheathing and liner is taken oerpendicular to the liner surface in order to assure tne location of sheathing at the required radial distance. The sheathing will be maintained at a radial distance from the liner of

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l'-3-3/8" for Group I Tendons and l'-8-5/8" for Grouo II Tendons within 3/4" tolerance.

(7) Chord distances between sheathinas will be used as a quide for installation of tne sneathing.

(8) After all sheathing has been installed and checked a general examination of sheathing will be cerformed to insure that no kinks exist in the sneathing tnat would orchibit the pulling of metallic clearing device which is pulled before, durino, and after every placement.

Accitional details on this methodology can be obtained from Houston Lignting 3 Power Engineering at the STP site.

We trust that tnis information will satisfy your concerns and that we can begin tne preparation steos to olace the three comolex cours in the Reactor Containment Building

'Jnit 1 dome immediately uoan notification from your office.

Very trulv yours,

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',4 O, y. d,r's d "Tr ?w.

'G Executive Vic/ President RAR/amj Attacnments

Houston Lighting & Power Company cc:

J. H. Goldberg May 7,1981

0. G. Barker ST-HL-AE-667 C. G. Rooertson SFN: C-0560 Howard Pyle Pace 3 R. L. Waldrop H. R. Dean D. R. Beeth J. D. Parsons km pann nRIGINM R. A. Frazar STP RMS H.'S. Phillios (NRC)

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

M. D. Schwarz (Raker & Rotts)

R. Gordon Gooch (Baker 3 Botts)

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

Director, Office of Inspection & Enforcerent Nuclear Regulatory Cornission Washington, D. C. 20555 M. L. Borchelt Charles Bechhoefer, Esouire President Chairnan, Atenic Safety & Licensino Board Central Power & Licht Company H. S. Nuclaar Reculatory Ccenission P. O. Box 2121 Washinoton, D. C.

20555 Corpus Christi, Texas 78403 R. L. Rance

• Dr. James C. Larh, III Central Power & Licht 313 Wondhaven Road P. O. Box 2121 Chapel Hill, f! orth Carolina 27514 Corous Christi, Texas 78403 R. L. Hancock Mr. Ernest E. Hill Director of Electrical Utilities Lawrence Livernare Labnratory City of Austin University of California.

P. O. Box 1088 P. O. Box 808, L-123 Austin, Texas 78767 Livernare, California 194550 T. H. Muehlenbeck Citizens for Equitaole Utilities, Inc.

City of Austin c/o Ms. Penoy Buchorn P. O. Box 1088 Route 1, Box 1684 Austin, Texas 78767 Brazoria, Texas 77J22 J. 8. Poston Pat Coy Assistant General Manaaer of Doeratinns Citizens Concerned About Nuclear Pnwer City Puolic Service Board 5106 Casa Oro P. O. Box 1771 San Antonio, Texas 78233

-San Antonio, Texas '78296 A. vonRosencerg Lanny Sinkin City ?uolic Service Board 2207-0, Nueces P. O. Bov 1771 Austin, Texts 78705 San Antonio, Texas 78296 3rian i. Kerwick, Esouire Jay Gutierrez, Escuire

. Assistant Attorney for the State of Texas Hearino Attorney P. O. Box 1254F Office of the Executive Leoal Director Caoitol Staticn U. S. Nuclear Renulatory Cornission Austin, Texas

/8711 Washincton, D. C.

20555

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