ML20090K588

RO 50-321/1984-04:on 840427,w/Unit 1 in Steady State & Unit 2 in Recirculation Pipe Replacement Outage,Level of Both Fire Protection Water Storage Tanks Dropped to Approx 195,000 Gallons Each.Caused by Matl Weakness in Fire Main

ML20090K588
Person / Time
Site:	Hatch
Issue date:	05/10/1984
From:	Nix H GEORGIA POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
GM-84-394, RO-1984-04, RO-1984-4, NUDOCS 8405240263
Download: ML20090K588 (2)

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(,*- . Georcb Power Company Post Office B:x 439 Baxley, Georgia 31513 '

Telephone 912 367 77h1 912 537-9445 b

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Edwin 1.q)lch h, Nucleet Plant GeorgiaFbwer rva May 10, 1984 GM-84-394 PLANT E. I. HATCH Special Report Docket No. 50-321 United States Nuclear Regulatory Commission Office of Inspection and Enforcement Region II Suite 3100 101 Marietta Street Atlanta, Georgia 30303 ATTENTION: Mr. James P. O'Reilly Attached is Special Report No. 50-321/1984-04. This report is required by Hatch Unit 1 Technical Specifications Section 3.13.2, ACTION b.1 and Hatch Unit 2 Technical Specifications Section 3.7.6.1, ACTION b.2.c.

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)GeneralManager

'ddb HCN/TLE/djs xc: R. J. Kelly G. F. Head J. T. Beckham, Jr.

P. D. Rice K. H. Gillespie S. B. Tipps .

R. D. Baker ,-

Control Room C0gj@'

'pd,b Document Control 9 e405240263 540510 PDR A00CK 05000321 S PDR r

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SPECIAL REPORT 50-321/1984-004 LICENSEE  : GEORGIA POWER COMPANY FACILITY NAME  : EDWIN 1. HATCH DOCKET NUMBER  : 50-321 DESCRIPTION Of EVENT:

On April 27, 1984, at approximately 2200 CST, with Unit 1 in steady-state operation at 2436 MWT (approximately 100% power) and Unit 2 in a recirculation pipe replacement outage, the level of both fire protection water storage tanks dropped to approximately 195,000 gallons each.

During an investigation on a ground fault alarm received on fire protection panel Z43-P005, an electronic spike was generated. This electronic spike tripped the fire detection circuits associated with fire protection panel Z43-P005 which in turn tripped six sprinkler systems. This started the electric fire pump. The 14 inch fire main header ruptured, resulting in a low fire main pressure which caused both diet el fire pumps to start. With a 14 inch fire main header ruptured and all three fire pumps running, a low fire water storage tank level was received in approximately 10 minutes. The level of both fire water tanks dropped below the requirements of Unit 1 Tech.

Specs, section 3.13.2. b and Unit 2 Tech. Specs. section 3.7.6.1.b.

(i.e., below 270,000 gallons each tank) before the fire main header rupture could be located and isolated. After isolating the fire main header rupture plant personnel restored the fire water storage tank levels to within both Unit 1 and Unit 2 Tech. Specs. limits in approximately 1 hour and 45 minutes. Also, a notification of significant events was made in accordance with 10 CFR 50.72 (i.e.,

event number 84-29).

The cause of the fire main header rupture was postulated as a material weakness in the fire main. This event is still being investigated.

The remainder of the fire Protection system performed as required.