ML17272A402

Deficiency Rept Re Pipe Whip Restraint Brackets W/Weld Defects in Electroslag Welds.Caused by Departure from Approved Electroslag Weld Procedures.Brackets Were Either Refabricated or Repaired

ML17272A402
Person / Time
Site:	Columbia
Issue date:	03/13/1979
From:	WASHINGTON PUBLIC POWER SUPPLY SYSTEM
To:
Shared Package
ML17272A401	List: ML17272A402
References
10CFR-050.55E, 10CFR-50.55E, GO2-79-40, GQ2-79-40, RO-790323, NUDOCS 7904300203
Download: ML17272A402 (2)

Text

Reportable Deficiency and Corrective Action For Defective Welds Found In Pipe Whip Restraint Brackets WASHINGTON PUBLIC POWER SUPPLY SYSTEM DOCKET No. 50-397 License No. CPPR-93 Nature of Deficienc Pipe whip restraint brackets used in supporting the Residual Heat Removal (RHR), Reactor Feed Water (RFW) and the t1ain Steam Piping System, inside containment, were found to have numerous weld defects in

-the electroslag welds. These defects consisted of slag inclusions and porosity, and have been documented on'R-78-1192 (215), NCR 215-03410 and PED 215-CS-0117. The weld deficiencies could only be a result of a departure from the approved electroslag weld procedure.

Safet Im lications If the welds were left uncorrected and were subjected to loads, as a result of a pipe, rupture, the weld defects could propogate causing the welds to crack and the pipe whip support brackets to fail. The failure of the pipe whip supports would therefore not restrain pipe whip which could cause damage to surrounding components and equipment, thus ad-versely affecting the safety of the -Nuclear Power Plant.

Corrective Action Taken Forty-five (45) pipe whip restraint brackets were fabricated using the Leckenby electroslag process. These bracket welds were evaluated using the radiographic and/or ultrasonic technique. Twenty (20) brackets were completely refabricated, fourteen (14) which obtained lesser defects were repaired and eleven (ll) were found to be acceptable. At this time all brackets have been installed in the plant.

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