ML20151U639

PNO-77-063:on 770420,plant Personnel Determined That Primary Containment Integrity Was Not Being Maintained as Determined by Containment Continuous Leak Monitoring Sys.Media Interest Expected Because of Close Attention Given to Facilities

ML20151U639
Person / Time
Site:	Yankee Rowe
Issue date:	04/21/1977
From:	Dreher F, Roy G, Thompson D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PNO-77-063, PNO-77-63, NUDOCS 9809110091
Download: ML20151U639 (1)

Text

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e PRELIMINARY NOTIFICATION -

April 21, 1977 PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-77-63 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.

Facility: Yankee Rowe (DN 50-29)

Yankee Atomic Electric Company .

Subject:

' SHUTDOWN DUE TO LOSS OF CONTAINMENT INTEGRITY With the plant operating at 95% power, plant personnel determined at 4:00 a.m.,

on April 20, 1977, that primary containment integrity was not being maintained as determined by the containment continuous leak monitoring system. The plant was shutdown at 10:30 a.m. and commenced a cooldown at 9:30 p.m. within the time frame established by the Technical Specifications. All containment penetrations have been examined for leakage; however, the source remains unidentified. The licensee has determined that the containment leakage has not resulted in exceeding radioactive gaseous release limits. The plant will remain shutdown until the leakage source is identified and repaired. NRC Region I (Philadelphia) will continue to follow the licensee's program.

t Media interest is expected because of close attention given to nuclear facilities. The Commonwealth of Massachusetts has been informed. A press i release is not planned at this time.

@4 Region I received notification of this occurrence by telephone call from

the Plant Superintendent at 9

00 a.m., April 21, 1977.

Contact:

FADreher, IE x27261 GWRoy, IE x27261 DThompson, IE x27541 Distribution: TransmittedHSt/.'N Chairman Rowden C. C. Kammerer, CA G. F. Murphy, JCAE Commissioner Gilinsky S. J. Chilk, SECY E. H. Whiteside, SCNR H. R. Myers, HCEE Transmitted: MNBB//Jf PBldgf.*NT SS Bldg 2..' S 0 ~

. L. V. Gossick, EDO E. G. Case, NRR C. V. Smith, NMSS /

S. H. Hanauer, EDO H. K. Shapar, ELD O/',

J. A. Harris, PA W. G. Mcdonald, MIPC Luge (MAIL) E. Volgenau, IE f R. C. Ryan, OSP T. J. McTiernan, OIA Region T M 0 0 PRELIMINARY NOTIFICATION b

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b 9809110091 770421 PDR I&E PNO-77-063 PDR _ _ . _ _ . _ _ . _ . _ . . . . _ _ . _ . .

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