ML20249B226

PNO-76-050:on 760319 & 22,through Wall Cracks Found in Two Isolable Sections of Cold Worked Six Inch Diameter,Schedule 80,A376 Type 304 Stainless Steel Pipe Elbows.Generic Implication Being Evaluated

ML20249B226
Person / Time
Site:	Nine Mile Point
Issue date:	03/23/1976
From:	Dreher F, Roy G, Thompson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-76-050-01, PNO-76-50-1, NUDOCS 9806220204
Download: ML20249B226 (1)

Text

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PRELI .iARY NOTIFICATION - NOT FOR,PUt.mC ISCLOSURE March 23, 1976 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -PNO-76-RN This preliminary notification constitutes EARLY notice of events of POSSIBLE safety or public interest significance. The information presented is as initially received without verification or evaluation and is basically all that is known by OIE staff as of 8:00 a.m. on date of this notification. IT SHOULD DE SPECIFICALLY NOTED THAT THIS NOTIFICATION MAY CONTAIN INFORMATION THAT LATER MAY BE DETERMINED TO BE INACCURATE OR INCONSISTENT. A'i 0FFICE OF INSPECTION AND ENFORCEMENT NOTIFICATION OF AN INCIDENT OR OCCURRENCE (BLUE SHEET) SUBSEQUENTLY WILL BE ISSUED IF WARRANTED.

Facility: Nine Mile Point Unit 1 (DN 50-220)

Niagara Mohawk Power Corporation

Subject:

THROUGH WALL CRACKS IN ISOLABLE PORTION OF REACTOR WATER CLEANUP SYSTEM PIPING Through wall cracks were found in two isolable sections of cold worked, six inch diameter, schedule 80, A376 type 304 stainless steel pipe elbows. " ,

I Apparently, the pipe elbows were not annealed following the cold bending operation. The pipe, located outside the drywell, carries reactor water to the Reactor Water Clean Up System (RWCUS) regenerative heat exchanger.

One crack was found March 19, 1976, and the elbow replaced on March 22.

A second crack was found March 22. Both cracks are similar to another crack found in the RWCUS on November 28, 1975.

The licensee shut the reactor down on March 22, to allow nondestructive examination of similar cold worked piping. The extent of the proposed  ;

outage is unknown. l

. 4 Generic implication are being evaluated. 0

/l i Media interest is expected because of continuing coverage of problems at I nuclear reactors. The State of New York has been informed. A press re-lease is not planned.

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Region I, Philadelphia, Pa received notification of the most recent . A i c i occurrence by telephone from the licensee at 1400, March 22. .2 !

Contact:

FADreher, IE x27261 GWRoy, IE x27261 DThompson, IE x27541 Distribution:

Chairman Anders Commissioner Mason S. J. Chilk, SECY Commissioner Gilinsky Commissioner Rowden G. F. Murphy, JCAE Commissioner Kennedy C. C. Kammerer, CA L. V. Cossick, J'. G. Davis, OIE J. A. Harris, PA B.' C. Rusche, NRR K. R. Chapman, NMSS J. La Fleur, ISP T.,J. McTiernan, AIA H. K..Shapara ELD Transmitted: PBldg[  ;

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.,, 3 PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE

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