ML19209D181

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Interim Deficiency Rept Re Unacceptble Bending of Welded Anchor Studs on Embedded Plates.Another Rept Will Be Forwarded by 800601
ML19209D181
Person / Time
Site: Hartsville, Phipps Bend  Tennessee Valley Authority icon.png
Issue date: 10/01/1979
From:
TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML19209D176 List:
References
NCR-HNP-A-064, NCR-HNP-A-64, NUDOCS 7910190501
Download: ML19209D181 (1)


Text

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ENCLOSURE HARTSVILLE AND PHIPPS BEND NUCLEAR PLANTS ALL UNITS

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UNACCEPTABLE BENDING OF WELDED STUD ANCHORS .

10 CFR 50.55(e) REPORT NO.1 (INTERIM)

NCR'S ENP-A-064 AND PBNP-039

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' On August 30 and 31,1979, TVA informed NRC-0II Inspector W. B. Swan, of a potentially reportable condition under 10 CFR 50.55(e) regarding unacceptable bending of welded stud anchors on embedded plates at the Hartsville Nuclear Plant aGd the Phipps Bend Nuclear Plact, 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 studs, etc.)

to varying angles in order to clear interferences during the placement of embedments for concrete pours. No instructions on bending of these welded stud anchors existed. Anchors bent may have been 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 drawings due to lack of specific instruction being provided by the design organizations to construction on how to handle embedment interferences.

CORRECTIVE ACTICN 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 corre.ctive 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.

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1174 275 7910190$ics /