ML19318D079

Second Interim Deficiency Rept Re Polar Crane Rail tie-down Studs.Investigation by Vendor Concludes That Acceptability of Polar Crane hold-down Studs Are Questionable.Brown & Root Will Further Evaluate Sys.Next Report to Be Sent 800801

ML19318D079
Person / Time
Site:	South Texas
Issue date:	06/23/1980
From:	Eric Turner HOUSTON LIGHTING & POWER CO.
To:
References
ST-HL-AE-484, NUDOCS 8007070306
Download: ML19318D079 (5)

Text

The Light ,_ im.u- n_,,.m. o-i -men company n _, uo,m,ea -

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June 23.1980 ST-HL-AE-484 SFN: V-0530 Mr. Karl Seyfrit-Director, Region IV Nuclear Regulatory Commission 611 Ryan Plaza Dri,e Suite 1000 Arlington, Texas 76102

Dear Mr. Seyfrit:

South Texas Project Units 1 & 2 Docket Nos. STN 50-498, STN 50-499 Second Interim Report on the Reportable Deficiency Concerning Polar Crane Rail Tie-Down Studs On March 20, 1980, pursuant to 10CFR50.55(e), Houston Lighting &

Power notified your office of a reportable deficiency concerning broken tie-down studs in the Reactor Containment Building Unit i polar crane rail system.

As specified in the first interim report (ST-HL-AE-449)

Houston Lighting & Power has directed Pittsburgh Des Moines Steel Company (PDM), the containment liner subcontractor, to perform an inspection and testing program in order to ascertain the integrity of th of the " hold-down" stud failure.

On April 16, 1980, PDM submitted the results of their investigation.

The results of this investigation can be sumarized as follows:

a. 480 of the 1248 total number of studs wcre reinspected visually and torque tested to 320 ft-lbs (the actual production test Of the 480 specified 318 ft-lbs for one in every 100 studs). studs ferential weld and 18 failed with the application of the torque test. The failed studs were identified by PDM as exhibiting an end condition similar to those that originally failed.

b. In reviewing the stud welding operator's qualifications, PDM identified that the operator's qualifications had been checked by torque testing rather than bend testing as required by the applicable code.

8007070 3e 6

flouston Lighting & Power Compan3 ST-HL-AE-484 SFN: V-0530 June 23,1980 Page 2

c. 294 studs were measured for as-welded length. Based on the stud lengths prior to welding, FDM identified that 57 were within 1/16" of the optimum after weld length and therefore acceptable. The remainder of the studs exceeded this re-quirement.

d. PDM's initial evaluation indicates that the stud weld was on the cold side. This evaluation was based on the fact that,l generally, the studs which failed did not have proper fusion under the flashing and contained a large amoup* of porosity.

PDM did indicate that the studs did have fus'ca approximately equal to the area of the stud base. Additionally, five of the failed studs were sent to the Nelson Stud Welding Company for their evaluation. The Nelson Stud Welding. Company has also concluded that the " hold-down" stud welds were on the cold side,

e. As requested, PDM performed additional testing of the stud welding process by welding several studs on to a 2h" SA-537 plate in the field using equipment and a set up similar to that used in the original qualifications. Results of this testing indicate that the stud welding procedure under which the actual work was performed should ha" produced acceptable stud welds.

f. Based upon their investigation, PDM has concluded that the acceptability of all the polar crane " hold-down" studs are questionable.

Houston Lighting & Fower has reviewed and concurred with the find-ings and conclusions contained above. However, Houston Lighting & Power has directed Brown & Root Engineering to further evaluate the as-built conditions for the polar crane rail system, and the crane operation in order to determine if any other causes contributed to the stud failures.

.The next interim report for this deficiency will be submitted to your office on August 1,1980.

Further questions should be directed to Mr. S. S. Rodgers, (713) 676-7953.

V ,

llointon Lighting & Power Compain ST-HL-AE-484 SFN: V-0530 June 23.1980 Page 3 Very truly yours, A. e E. A. Turner Vice President Power Plant Construction

& Technical Services RRH/nnf

Houston W.tg & Pmer Company ST-HL-AE- 484 Page 4 cc: G. W. Oprea, Jr.

D. G. Barker C. L. McNeese H. R. Dean R. L. Waldrop G. B. Painter A. J. Granger R. A. Frazar M. D. Schwarz (Baker & Botts)

R. Gordon Gooch (Baker & Botts)

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

Director, Office of Inspection & Enforcement Nuclear Regulatory Commission Washington, D.C. 20555 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 M. C. Nitcholas City of Austin P. O. Box 1088 Austin, Texas 78767 J. B. Poston Assistant General Manager of 0, i. --'.lons City Public Service Board ,

P. O. Box 1771 San Antonio, Texas 78296 A. vonRosenberg City Public Service Board P. O. Box 1771 San Antonio, Texas 78296

Houston (Jrhting & lbwer Company ST-HL-AE- 484 -

Page 5 Charles Bechoefer, Esquire Cnairman, Atomic Safety & Licensing Board U.S. Nuclear Regulatory Conmission Washingter, D.C. 20555 Dr. James C. Lamb III 313 Woodhaven Road Chapel Hill, North Carolina 27514 Dr. Emmeth A. Luebke Atomic Safety & Licensing Commission U.S. Nuclear Regulatory Commission Washington, D.C.20555 Steven A. Sinkin Esquire 116 Villita Street San Antonio, Texas 78205 l l

Citizens for Equitable Utilities j c/o Ms. Peggy Buchorn '

Route 1, Box 432 Brazoria, Texas 77422 l

Richard W. Lowerre Esquire Assistant Attorney General for the State of Texas j P. O. Box 12548 Capitol Station j Austin, Texas 78711 Henry J. McGurren Esquire  !

i Hearing Attorney Office of the Executive Legal Director U.S. Nuclear Regulatory Commission Washington, D.C. 20555 .

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