ML20085C948

AO 50-254/74-33:on 741012,pin Hole Leak Discovered at Elbow Socket Fillet Weld on 1 Inch Instrument Sensing Line 1-261-3C.Caused by Slag Inclusion Developed During Intial Weld.Elbow Socket Rewelded

ML20085C948
Person / Time
Site:	Quad Cities
Issue date:	10/22/1974
From:	Kalivianakis N COMMONWEALTH EDISON CO.
To:	Oleary J US ATOMIC ENERGY COMMISSION (AEC)
Shared Package
ML20085C950	List: ML20085C948 ML20085C957
References
AO-50-254-74-33, NJK-74-342, NUDOCS 8307130259
Download: ML20085C948 (2)

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NJK-74-342 October 22, 1974 -

Mr. John F. O' Leary, Director Directorate of Licensing Regulation U. S. Atomic Energy Comission Washington, D. C. 20545

REFERENCE:

Quad-Cities Nuclesr Power Station Docket No. 50-254, DPR-29 Appendix A, Sections 1.0.A.5, and 6.6.B.1.a

Dear Mr. O' Leary:

Enclosed please find Abnormal Occurrence Report No. 50-254/74-33 for Quad-Cities Nuclear Power Station. This occurrence was previously reported to Region III, Directorate of Regulatory Operations by telephone on October 12, 1974 and to you and Region III, Directorate of Regulatory Operations by telecopy on October 12, 1974 This report is submitted to you in accordance with the requirements of Technical Specification 6.6.B.1.a.

Very Truly Yours, COMjoUiEALTH EDISON C0!?PANY C.UAD-ClTIES IRICLEAR PGdER STATION ads . $

N. J. Kalivianakis Station Superintendent NJK/LDR/rhb cc: Region III, Directorate of Regulatory Operations J. S. Abel O chhf4 PDR 103$$

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I REPORT NU?GER: 50-254/74-D REPORT DATE: October 22, 1974 OCCURRENCE DATE: October 12, 1974 FACILITY: Quad-Cities Iluelear Power Station Cordova, Ill. 61242 IDEf?PIFICATIO!I 0? OCCURRET:CE:

Pin hole leak on 1 inch instrument sensing line 1-261-3C COMDITIO!IS PRIOR *O OCCURRT'CE:

Drywell inspection during Unit start-up. O megawatts electrical Rx critical.

DESCRIPTIO!! OF OCCURRE?!CE:

At approximately 0040 hours4.62963e-4 days <br />0.0111 hours <br />6.613757e-5 weeks <br />1.522e-5 months <br /> on October 12, 1974, inspection of Unit One drywell equipment during start-up operations resulted in the discovery of a pin hole leak at an elbow socket fillet weld on 1 inch carbon steel instrument sensing line 1-261-3C. Start-up operations were terminated and Unit One shut-down. The weld was dye penetrant tested, completely ground out and rowelded.

The new weld was then dye penetrant tested and visually inspected using a magnafying glass and found to be satisractory.

DESIGNATIO!i OF APPART77 CAUSE OF OCCURRE?'CE:

Installation / Construction.

The apparent cause of the pin hole leak was due to a slag inclusion developed at the time of the initial weld. I!ormal vibration of the line furthered the inclusion to develop into the resulting pinhole.

ANALYSIS OP OCCURREIEE:

Safety implications to safe operation of the plant, plant personnel, and the health and safety of the eblic were minimal. I!o reactor safety system was affected that would have prevented a safe shut down of the reactor.

CORRPCTIVE ACTION:

Corrective actions included the unit shutdown and dye penetrant testing to find the cause of the pin hole leak. Further corrective actions included rewelding the elbow socket and inspecting the new weld to assure its acceptability, These corrective actions are considered to be sufficient to resolve this

. occurrence and no further corrective action is contemplated.

FAITURE DATA:

This is the first such occurrence involving weld imperfections affecting Instrument Sensing Lines or similar equipr.ent. I!o cumulative experience can be forwarded within this report in light of this, and no safety implications can be concluded relating to cu :ulative experiences of similar systems or components.

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