ML20236U225

PN-75-036:on 750613,DPC Notified Region II That Following Turbine Trip,Primary Sys Pressure Increased Where Primary Sys Electromatic Rv Opened to Reduce Pressure.Rv Stuck in Open Position & Pressure Reduced in 30 Minutes

ML20236U225
Person / Time
Site:	Oconee
Issue date:	06/13/1975
From:	Jennifer Davis, Thornburg H, Warnick R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PN-75-036, PN-75-36, NUDOCS 9807290393
Download: ML20236U225 (1)

Text

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PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE June 13, 1975 f') ' PRELIMINARY ~ NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PN-75-36 (Revised)

This preliminary notification constitutes EARLY notice of events of

..e POSSIBLE safety or pablic 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 4:45 p.m. on date of this notification. IT SHOULD BE SPECIFICALLY NOTED THAT THIS NOTIFICATION MAY CONTAIN INFORMATION THAT LATER MAY BE DETERMIhTD TO BE INACCURATE OR INCONSISTENT. AN OFFICE OF INSPECTION AND EliFORCEMENT NOTIFICATION OF AN INCIDENT OR OCCURRENCE (BLUE SHEET) SUBSEQUENTLY

- -WILL BE ISSUED IF WARRANTED.

-Facility: Oconee Unit 3 Duke Power Company

Subject:

PRIMARY SYSTEM RAPID DEPRESSURIZATION Duke Power Company notified the Region II office of Inspection and Enforcement by telephone that following a turbine trip, primary system pressure increased to 2255 psig where the primary system electromatic relief valve opened to reduce pressure. The electromatic relief valve

. stuck in the open position and primary system pressure was reduced to 760 psig in about 30 minutes. The depressurization was te'rminated  %

- by closing a block valve in the same line as the relief valve. Cooldown rate limits of the primary system were not violated. Licensee is continuing normal cooldown.

OIE received notification of this occurrence by telephone from Oconee site at 4:30 p.m. on 6-13-75. j

Contact:

RFWarnick, IE x726'. HDThornburg, IE x7353, JGDavis, IE x7541 Distribution:

Chairman Anders Commissioner Mason S. J. Chilk, SECY Commissioner Gilinsky Commissioner Rowden G. F. Murphy, JCAE g Cor:missioner Kennedy C. C. Kammerer, CA f

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L. V. Gossick, EDO D. F. Knuth, IE J. A. Harris, PA ,

B. C. Rusche, NRR H. H. Brown, ISP K. R. Chapman, NMSS H. K. Shapar, ELD -

G, Transmitted: P Bldg

H St MNBB 2 PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE

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9807290393 750613 PDR I&E ,

PN-75-036 PDR ,