ML20101C657

Responds to IE Bulletin 80-13, Cracking in Core Spray Spargers. Visual Insp of Core Spray Spargers & Associated Piping Performed.Circumferential Crack Discovered in heat- Affected Zone of Lower Sparger to T-box Weld

ML20101C657
Person / Time
Site:	Hatch
Issue date:	11/21/1984
From:	Gucwa L GEORGIA POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
References
IEB-80-13, NED-84-588, TAC-55236, NUDOCS 8412210158
Download: ML20101C657 (2)

Text

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m Georg'a Power Company 6

333 Piedtront Avenue Atlanta. Georgia 30308 -

Teleptme 404 526 6526

. Maihng Address:.

Post Office Box 4545 At!anta. Georgia 30302 3'l NOV 29 Afg.

Georgia Power L T. Gucwa the sauthern eiectrc system.

Manager Nuclear Eng neenng NED 84-588 and Chief Nucfear Engineer Novenber 21, 1984 i

~ U.' S. Nuclear Regulatory Consission REE'ERENCE:

l Office of Inspection and Enforcement RII: JPO 1

-Region II - Suite 2900 50-321 101 Marietta Street, IM I&E Bulletin f

Atlanta, Georgia 30323 80-13 ATTENTION: Mr. Janes P. O'Reilly i

GENIUMEN:

. Pursuant to the requirenents of I&E Bulletin 80-13, " Cracking in' Core Spray Spargers", visual inspection of the Hatch Unit 1 core spray spargers

[

and associated piping has been performed during the, refueling /naintenance outage currently in. progress.

A renote, underwater. television canera (having the required capability of in situ viewing of 0.001 inch fine wires) was used for the inspection.

. A circtnferential crack was discovered in the heat-affected zone of the lower sparger to T-box weld (approximately 1/8 inch fra the weld).

It spans at least 1800 of circumference and is approximately 0.010 inch wide, i

i.

Evaluation of the cracking has been performed by General Electric Company.

%e cause is suspected to be stress corrosion cracking resulting-

.from cold work and sensitization during fabrication and installation of the sparger.

An analysis was performed to determine the acceptability of continued operation, using the conservative asstaptions that the crack spanned 3600 of circtanference, was through-wall, and that no clanping device was installed on the sparger.

%e analysis considered structural effects, the -possibility of loose parts, and the effect on IDCA analysis.

It was denonstrated - that operation with the core spray sparger in the conservatively assmed condition would not result in any safety concern.. A report doctmenting ' the evaluation performed will be transnitted prior to 4

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. unit startup.

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m**d8ait'otna G

PDR

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GeorgiaPower d U. S. Nuclear Regulatory Comission Office of Inspection and Enforcement Region II - Suite 2900 November 21, 1984-Page 2 Although the analysis shows that it is not necessary, GPC has elected to install a clanping device designed to maintain the structural integrity of the sparger.

Installation of this device will provide added assurance that continued operation will result in no safety concern.

Please contact this office if there are any questions.

Very truly yours, W *[ Q:

?

L. T. Gucwa JH/jh xc: J. T. Beckham, Jr.

H. C. Nix, Jr.

Senior Resident Inspector NRC Office of Inspection and Enforcetent, Division of Reactor Operations Inspection

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