ML20151X431

PNO-76-002:on 760106,during Startup,Significant Flow Transient in Feedwater Sys Occurred.As result,4 Inch Feedwater Regulating Bypass Valve Had Valve Yoke Failure Which Resulted in Ejection of Valve Stem

ML20151X431
Person / Time
Site:	Pilgrim
Issue date:	01/07/1976
From:	Jennifer Davis, Dreher F, Roy G NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-76-002, PNO-76-2, NUDOCS 9809170088
Download: ML20151X431 (2)

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1 PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE 1

January 7, 1976 l PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -PNO-76-02 .

This prel;Lminary notification constitutes EARLY notice of events 6f 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 10:00 a.m. on date of this notification. IT SHOULD BE SPECIFICALLY NOTED THAT THIS NOTIFICATION MAY CONTAIN INFORMATION THAT LATER MAY BE DETERMINED TO BE INACCURATE OR INCONSISTENT. AN OFFICE OF INSPECTION AND ENFORCEMENT NOTIFICATION OF AN INCIDENT OR OCCURRENCE (BLUE SHEET) SUBSEOUENTLY WILL BE ISSUED IF WARRANTED.

Facility: Pilgrim 1 ,

Boston Edison Company (50393)

Subject:

FAILURE OF 4 INCH FEEDWATER REGULATING BYPASS VALVE During a startup ar 9:15 a.m. on January 6. 1976, a significant flow transient in the feedwater system occurred. As a result, the 4 inch feedwater regulating bypass valve had a valve yoke failure which resulted in the

.,' ejection of the valve stem with a subsequent loss of several hundred -

gallons of high temperature, low activity water and stum th, rough the one inch hole. , , ,

The reactor was shutdown without incident.

. The valve is located in the turbine building condenser bay area and is l in a non-safety related system. The feedwater line has two series check

, valves and a manual valve between the reactor and the failed valve.

As an apparent consequence of the force of the stem ejection, the valve body was reported to have a 360 degree circumferential crack which-does - - -

not appear to be through wall.

There were no personnel injuries or releases to the station or environment

. above regulatory limits. A scheduled refueling outage may be advanced 10 days because of this event.

i Con.tinued 9809170088 760107 D PDR I&E 3 PNO-76-OO2 PDR .

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Continued January 7, 1976 Page 2 PNO-76-02 l Media interest is expected because of local, state and intervenor sensitivity j to problems at Pilgrim 1 and Pilgrim 2. The State of Massachusetts has been informed. A press release is not planned. The licensee plans to announce the refueling outage with reference to a valve failure.

RRC, Region I, Philadelphia, Pa. received notiiication 'of this occurrence by telephone from licensee at 4:45 p.m. on 1/6/76. Further information was obtained at 9:00 a.m. on 1/7/76. {

Contact:

FADreher, IE x27261 G E oy, IE x27353 JGDavis, IE x27541 l

l' 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. Gossick, EDO D. F. Knuth, IE J. A. Harris, PA B. C. Rusche, NRR J. La Fleur, ISP T. J. McTiernan, AIA  !

K. R. Chapman, NMSS H. K. Shapar, ELD Transmitted: P Bldg /X' 1-; E St /d.* /^t ; MNBB /4 .* 'I" , Luge .-

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PRELIMINARY NCTIIFICATION - NOT FOR PUBLIC DISCLOSURE l i

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