ML19209B558

Forwards Interim Rept on Unacceptable Bending of Welded Stud Anchors on Embedded Plates.Caused by Const Forces Not Following Design Drawings.Testing Program Being Initiated to Determine Effects of Bending

ML19209B558
Person / Time
Site:	Hartsville, Phipps Bend
Issue date:	10/01/1979
From:	Mills L TENNESSEE VALLEY AUTHORITY
To:
References
NUDOCS 7910100120
Download: ML19209B558 (2)

Text

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TENNESSEE VALLEY AUTHORITY C H A T T A N OO ., A . T E N P. E S S E E 3 7-101 400 Chestnut Street Tower II October 1, 1979 Mr. J:mos P. O'Reiliy, Director Office of Inspection and Enforcement U.S. Nuclear Rsgulatory Cornission Regior. II - Suite 3100 101 Mcrietta Street Atlanta, Georgia 30303

Dear Mr. O'Reilly:

HARTSVILLE AND PHIPPS BEND NUCLEAR PLANTS ALL UNITS - REPORTABLE DFFICIENCY - UNACCEPTABLE BENDING OF WELDED STUD ANCEORS ON C'1EDDED PLATES (NCR'S ENP-A-064 AND PBNP-039)

Initial report of the subject deficiency was made to W. B. Swan, NRC-OIE, Regica II, on August 30, 1979, for the Hartsville Nuclear Plant and on Au wat 31, 1979, for the Phipps Band Nuclear Plant. In compliance with tragraph 50.35(e) or 10 CFR Part 50, we are enclosing the first icter's report of the subject deficiency. We anticipate transmitting anoth report to NRC-01E on or before June 1, 1980. If you have any q.astions regarding this matter, please call Tish Jenkins at FTS 8 '-2014.

Very truly yours, TEK.'ESSEE VALLEY AUTHORITY L. M. Mills, Manager Nuclear Regulation and Safety Enclosure ,

cc: l'r, Victor Stallo, Director (Enclosure)

Office of Inspection and Enforcement i U.S. Nuclear Rcgulatory Connission Washington, DC 20555 .

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ENCLOSURE HARTSVILLE AND PHIPPS BEND NUCLEAR PLANTS ALL UNITS UNACCEPTABLE BENDING OF WELDED STUD ANCHORS 10 CFR 50.55(e) REPORT NO. 1 (INTERIM)

NCR'S HNP-A-064 AND PSNP-039 on August 30 and 31, 1979, TVA informed NRC-0IE Inspector W. B. Swan, of a potentially reportable condition under 10 CFR 50.55(e) ragarding unacceptable bending of welded stud anchors on embedded plates at the Hartsville Nuclear Plant and the Phipps Bend Nuclear Plant, respectively.

This is the first interim report on this deficiency. We anticipate transmitting another report to NRC-0IE on or before June 1, 1980.

DESCRIPTION OF DEFICIENCY Construction personnel were bending welded stud anchors (. Nelson deuds, etc.)

to varying angles in order to clear interferences during the placement of embedments for concrete pours. "o instructions or bending of these welded stud anchors existed. Anc.. rs bent may have b'en designed to carry tension loads and the bending could reduce the capability of the embedment to perform as intended by the designer.

CAUSE OF THE DEFICIENCY The cause of the deficiency is the construction forces not following design drawfigs due to lack of specific instruction being provided by the design organizations to construction on how to handle embedment interferences.

CORRECTIVE ACTION Interim instructions have been developed and issued by the Division of Engineering Design to the construction organization on permitted bending of welded stud anchors (studs). A testing program is being initiated to determine the effect of bending of the studs on the capability of the embedment to perform as designed. The results of the test program will be used to develop final criteria on the bending of the studs.

Other corrective action will be addressed in the next report on this deficiency.

Investigations are being made to determine if other TVA plants are affected by this deficiency.