05000287/LER-1982-003, Forwards LER 82-003/01T-0.Detailed Event Analysis Encl

Forwards LER 82-003/01T-0.Detailed Event Analysis Encl

ML20050A966
Person / Time
Site:	Oconee
Issue date:	03/11/1982
From:	Parker W DUKE POWER CO.
To:	James O'Reilly NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION II)
Shared Package
ML20050A967	List: 05000287/LER-1982-003, Forwards LER 82-003/01T-0.Detailed Event Analysis Encl 05000287/LER-1982-003-01, /01T-0:on 820211,steam Generator Tube Leak of Approx 0.01 Gpm Indicated by Condensate Steam Air Ejector Offgas Monitor.Caused by Erosion of Tube at Point 31 Inches Above Fifteenth Tube Support Plate.Tube Explosively Plugged
References
NUDOCS 8204020455
Download: ML20050A966 (2)

LER-1982-003, Forwards LER 82-003/01T-0.Detailed Event Analysis Encl

Event date:
Report date:
2871982003R00 - NRC Website

text

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o Dunn Powen COMPANYz 3.,

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March 11, 1982 ruc.-o~c.

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Mr. James P. O'Reilly, Regional Administrator f

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U. S. Nuclear Regulatory Commission 3

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Re: Oconee Nuclear Station QK,g p/,;

Docket No. 50-287 s'

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Dear Mr. O'Reilly:

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Please find attached Reportable Occurrence Report R0-287/82-03. This report is submitted pursuant to Oconee Nuclear Station Technical Specification 6.6.2.1.a(3), which concerns an abnormal degradation of the reactor coolant pressure boundary. This report describes an incident which is considered to be of no significance with respect to its effect on the health and safety of the public. My letter of February 25, 1982 addressed the delay in the preparation of this report.

Very truly yours, Jt6 )[ 4l.)r1 f- (k y/c W tlC

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William O. Parker, Jr.

[-/f JFK/php Attachment cc: Director Records Center Office of Management & Program Analysis Institute of Nuclear Power Operations U. S. Nuclear Regulatory Commission 1820 Water Place Washington, D. C. 20555 Atlanta, Georgia 30339 Mr. W. T. Orders Mr. Philip C. Wagner NRC Resident Inspector Office of Nuclear Reactor Regulation Oconee Nuclear Station U. S. Nuclear Regulatory Commission Washington, D. c. 20555 OFFICIAL COPY L

0204020455 B20311 DR ADOCK 05000 g

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I DUKE POWER COMP [RY OCONEE NUCLEAR STATION UNIT 3

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l Report Number: R0-287/82-03 j

Report Date: March 11, 1982 Occurrence Date: February 11, 1982 I

Facility: Oconce Unit 3, Seneca, South Carol?ia i

1 Identification of Occurrence:

3A Steam Generator tube leak i

i Conditions Prior to occurrence:

100% FP i

Description of Occurrence: On February 11, 1982, a steam generator tube leak a

' developed on the 3A steam generator, as indicated by an increase in the 3RIA-40 count level. Based on the radiation count level increase the leak rate was l

0.01 gal / min and increased to 0.03 gal / min until February 15, 1982 when the j

unit was shut down for repair of the leak.

I j

Apparent Cause of Occurrence: The apparent cause of the tube leak was erosion of the tube at a point 31 inches above the fifteenth tube support plate. Fiber-

]

scope inspection'shows a round hole with apparent corrosion around the edge.

i The corrosion and shape of the hole indicate pitting with some erosion on the defective tube, 1

l Analysis of Occurrence: Tube 2-4 has not had an eddy current test prior to the Icak occurring. Personnel and systems adequately controlled this event j

and the releases were well within regulatory requirements. Thus, it is con-i sidered that the health and safety of the public were not affected by this

]

event.

1

Corrective Action

The reactor was shut down, and the leaking tube identified

)

as Tube 2-4, which was stabilized from the top and was explosively plugged l

from the bottom.

Eddy current testing was conducted on a selection of 150 tubes using the following criteria:

1) tubes in the area of the leaking tube, j

2) tubes at the tube bundic edge near the auxiliary feedwater header dowel pins, 3) ten tubes in each of the lane rows, and 4) all tubes with previous i

j through wall indications between 20% and 40%. Tube 75-118 was found to have a 52% through wall indication, and was explosively plugged from the top and the bottom. Tube 75-118 had a 25% through wall indication at the fourteenth tube support plate during eddy current testing conducted in December 1980.

i No other defective tubes were found during this eddy current testing.

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