ML19305A807

Interim Deficiency Rept Re Weld Deficiencies in Reactor Pressure Vessel Shield Wall.Of 25 Welds inspected,17 Were Found to Be of Unacceptable Quality.Backing Bar Will Be Stripped from First Two Shells of Wall

ML19305A807
Person / Time
Site:	Hartsville
Issue date:	03/13/1980
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML19305A806	List: ML19305A805 ML19305A807
References
NCR-HNP-A-087, NCR-HNP-A-87, NUDOCS 8003180377
Download: ML19305A807 (1)

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l ENCLOSURE HARTSVILLE NUCLEAR PLANT UNIT Al RPV SHIELD WALL - WELD DEFICIENCIES NCR ENP-A-087 .

10 CFR Part 50.55(e) -

REPORT NO. 1 (INTERIM)

On February 15, 1980, TVA informed NRC-0IE Region II Inspector, R. W. Wright, of a potentially reportable condition under 10CFR50.55(e) regarding welds of questionable quality on the reactor pressure vessel (RPV) shield wall structure supplied by Industrial Engineering Works (IEW), Trenton, New Jersey. This is the first interim report on this deficiency. TVA anticipates transmitting the final report on or before May 30, 1980.

Description of Deficiency This deficiency was discovered when TVA was making repairs on the unit Al RPV shield wall structure per NCR HNP-A-059 (not significant). HNP-A-059 concerns the mismatch of RPV shield wall stiffeners where the stiffeners attach to the skin plate between tier one and tier two. The backing bar was removed for approximately 12 inches in order to properly align the stiffener bars for welding. However, when the backing bar was removed, it was observed that a weld between a vertical stiffener and shell plate had an area of lack of penetration, slag, and lack of fusion. TVA removed more backing bars in order to examine other welds. Of the 25 welds inspected, 17 were found to be of unacceptable quality. As a result, TVA will completely strip all of the backing bar from the first two shells of the RPV shield wall in order to determine the extent of the nonconformance.

Safety Implications This will be discussed in the final report.

Corrective Action Welds of unacceptable quality will be removed and rewelded to meet acceptable criteria. Any further corrective action will be discussed in the final report.

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