ML19210F030

RO-79-089:on 791106,while Evaluating as-built Seismic Piping & Supports,Head Vent Line Portion of RHR Head Spray Piping & Bypass to Condenser Valve Chest Found Unsupported.Caused by Omission of Supports from Design

ML19210F030
Person / Time
Site:	Hatch
Issue date:	11/06/1979
From:	Manry M GEORGIA POWER CO.
To:
References
NUDOCS 7912130426
Download: ML19210F030 (2)

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R0 TELEGRAM FOR 'AT 01 BAXLEY, GA. 31513 FMS MR. JAMES P. O'REILLY UtlITED STATES f;UCLEAR REGULATORY COMMISSIO:1

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DIRECTOR OF ItiSPECTIOl AtiD EliFORCEMEtlT REGIC:1 II SUITE 31C0 101 MARIETTA STREET ATLAtiTA, GEORGIA 30303 ,

SUEJECT: HATCH U:;IT I, DC:V,ET N0. 50-321, 10TIFICATICN CF REPORTAELE OCCURRENCE tio. 50-321/1979-089 t10TIFIED: Ross F. Rogers DATE: 11-6-79 CATE: 11-6-79 TIME: 15:00 EST DESCRIPTION OF REPORTABLE OCCURRENCE Initial Conditicn This occurrence was discovered by A/E while evaluating as-built seismic piping and supports per the requirements of IE Bulletin 79-14. Unit I was operating at full power at the time.

Nature of Occurrence It was found that the following system piping is not supported seismic class I: the head vent line near valves B21-F003 & F004; a portion of RHR head spray piping near valve E11-F023; the bypass to condenser valve chest.

Immediate Corrective Action The RHR piping has been modified since the evaluation was performed. This was accomplished per design change request 79-423. A design modification will be generated to provide seismic class I support for the by pass to con-denser valve chest and the reactor head vent lines near valve B21-F003 and F004.

Cause These supports were omitted from .the original design.

Sucolemental Corrective Action '

The aforementioned modification on the bypass valve chest will be implement-ed during the next cold shutdown. Additional supports will be designed for the head vent piping and the change will also be implemented during the .

next cold shutdown.

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Status of Redundant or Backuo Systems fio redundant supports exist for any of these system portions.

Impact to Other Unit l No other units were affected by this event.

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Justification for Continued Operation Even if this unlikely seismic event did occur there would exist no threat to public health or safety for the following reasons. The RHR line supports have been modified; therefore, this item is no longer considered a problem. The bypass to condenser valve chest is downstream from the MSIV's and would be automatically isolated in the event of a line rupture. The worst case wculd be the ru;;ture of the two inch head vent line. Such an event is an analyzed accident for this unit. Any release of steam would be inside the primary con-tainment. Tione of the above situations would prevent a safe shutdcwn, nor would they pose any threat to public health or safety.

7 N b j M'. Ma'rtry g Plant Managpf-1552 526 I

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