ML19312E326

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Second Interim Deficiency Rept Re Weld Deficiencies on Reactor Pressure Vessel Shield Wall.All Backing Bars Removed from Weld Joints Between Stiffeners & Shell Plate. Welds Will Be Repaired
ML19312E326
Person / Time
Site: Hartsville Tennessee Valley Authority icon.png
Issue date: 05/29/1980
From:
TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML19312E322 List:
References
NCR-HNP-A-087, NCR-HNP-A-87, NUDOCS 8006040233
Download: ML19312E326 (1)


Text

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ENCLOSURE HARTSVILLE NUCLEAR PLANT UNIT A1 RPV SHIELD WALL - WELD DEFICIENCIES NCR HNP-A-087 10CFR PART 50.55(e) c; REPORT NO. 2 (INTERIM)

On February 15, 1980, TVA informed NRC-OIE 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 second interim report on this deficiency. TVA anticipates transmitting the next report on or before September 26, 1980.

Description of Deficiency This deficiency was discovered when TVA was making repairs on the unit A1 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 remcved for approximately 12 inches in order to properly align the stiffener bars for welding. However, when the backing bar was removed, itwas observed that a weld between a vertical stiffener and shell plate had an area of lack of penetration, slag, and lack of fusion.

There are 48 stiffener-plate-to-skin-plate welds per tier in this structure, each approximately 12 feet in length.

Interim Prcgress 1

TVA removed areas of backing bar in order to examine other welds.

Numerous welds of poor quality were found. As a result, all backing bars were removed from weld joints between stiffeners and shell plate on tier one and tier two. All welds exhibited areas of poor quality and unacceptable ccnditicns. These welds will be repaired to meet acceptable criteria. TVA will also inspect the other tiers which have been fabricated and make any necessary repairs.

s 80 8604 02M .5