ML20249B313

PNO-76-086:on 760403,reactor Was Shutdown to Remove Reactor Vessel Surveillance Specimens.Insp of Stator Disclosed That 11 Coils Faulted (Shorted or Grounded).Rewinding of Only 11 Coils Would Extend Current Outage Until July 1976

ML20249B313
Person / Time
Site:	Rancho Seco
Issue date:	05/11/1976
From:	Roy G, Thompson D, Whitt K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-76-086, PNO-76-86, NUDOCS 9806220309
Download: ML20249B313 (1)

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PRELIMINARY NOTIFICATION i

May 11, 19/b PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-76-86 This preliminary notification constitutes EARLY notice of an event 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 IE staff on this date.

I FACILITY: Rancho Seco (DN 50-312)

I S'acramento Municipal Utility Distric i

SUBJECT:

EXTENDED OUTAGE TO REPAIR MAIN STATION GENERATOR On April 3, 1976, the reactor was shut down to remove the reactor vessel surveillance specimens (a generic problem with B&W reactors).

l During this outage, the licensee ascertained that most of the wedges for positioning the main station generator stator coils

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had become dislodged.

Inspection of the stator disclosed that eleven coils were f aulted (shorted or grounded). Rewinding of only these eleven coils would extend the current outage until July 1976.

Should SHUD elect to completely rewind the stator, -

the licensea estimates that the outage will be extended until.

October 1976.

Media interest is anticipated in the California area because of the i

Nuclear Initiative.

i Region V (Walnut Creek, CA) received notification of the stator i

coil inspection results by telephone on May 10, 1976, for the i

Plant Technical Assistant.

Contact:

KWhitt, IE x27261

GWRoy, IE x27261 DThompson, IE x 27541 Distribution:

ffo, i

Chairman Rowden Commissioner Mason S. J. Chilk, SECY Commissioner Gilinsky C. C. Kammerer, CA G. F. Murphy, JCAE O

Commissioner Kennedy L. V. Gossick, EDO E. Volgenau, OIE J. A. Harris, PA B. C. Rusche, NRR J. La Fleur, ISP T. J. McTiernan, AIA K. R. Chapman, NMSS H. K. Shapar, ELD 5

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