ML20236U427

PN-75-058:on 750728,util Notified Region II That Reactor Blowdown from (95% Power) About 1005 Psi to About 430 Psi Occurred When 7 ADS Relief Valves Opened Simultaneously. Licensee Will Inspect Torus Before Returning to Power

ML20236U427
Person / Time
Site:	Hatch
Issue date:	07/30/1975
From:	Jennifer Davis, Gower G, Thornburg H NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
To:
References
PN-75-058, PN-75-58, NUDOCS 9807300139
Download: ML20236U427 (1)

Text

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PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE July 30, 1975

(" PRELIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE -- PN-75-58 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 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) SUBSEQUENTLY ,

, WILL BE ISSUED IF WARRANTED.

. . .. Facility: .E. I. Hatch, Unit 1, Georgia Power Company (DN-50-321)

Subject:

INADVERTENT REACTOR BLOWDOWN The Georgia Power Company notified a Region II Reactor Inspector that a reactor blowdown from (95% power) about 1005 psi to about 430 psi occurred at 11:50 pm July 28, 1975, when the 7 automatic depressurization system (ADS) relief valves opened simultaneously.

An automatic reactor scram occurred when the main steam isolation valves closed as a result of reactor pressure dropping below 880 psi with the reactor in the "run" mode. The seven relief valves were e

_.open for about 15 seconds. At the time of the blowdown, an operator F was attempting to demonstrate that the ADS logic was operable, and inadvertently installed an electrical jumper that actuated the ADS.

(

The licensee will inspect the torus before returning to power. The Region II inspector is evaluating the occurrence onsite.

The Region is not aware of any news release on this event at this time. A news release may be issued by the Region depending upon the outcome of the torus inspection now in progress.

OIE (Region II) received notification of this occurrence by telepnone from D. G. Hinckley, our inspector who was at the site, at approximately Q 8:00 a.m. on 7/29/75. /

/

Contact:

GCGover, IE x7353 HDThornburg, IE x7353, JGDavis, IE x7541 Distribution:

Chairman Anders Commissioner Mason

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S. J. Chilk, SECY O Commiss$soner Gilinsky- Com=2ssioner Rowden G. F. Murphy, JCAE. . . .2g Commissioner Kennedy C. C. Kammerer, CA )

L. V. Gossick, EDO D. F. Knuth, IE J. A. Harris, PA B. C. Rusche, NRR H. H. Brown, ISP T. J. McTiernan, AIA K. R. Chapman, HMSS H. K. Shapar, ELD Transmitted: P Bldg  ; H St  ; MNBB  ; Luge PRELIMINARY NOTIFICATION - NOT FOR PUBLIC DISCLOSURE

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