ML20071H964

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Submits Daily Highlights Re Insp of Ruptured Tube Using Fiber optics.Five-inch Kite Shaped Rupture Caused by Stress Corrosion Linked to Differential Expansion Between Tube & Tube Wrapper Wedge.Tube Being Plugged
ML20071H964
Person / Time
Site: 05000000, Ginna
Issue date: 02/08/1982
From: Lyons J
Office of Nuclear Reactor Regulation
To: Carter J, Harold Denton, Eisenhut D
NRC
Shared Package
ML19302F297 List:
References
FOIA-82-309 NUDOCS 8203100593
Download: ML20071H964 (1)


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o, U**lTED STATES 8

NUCLEAR REGULATORY COMMISSION o

qE WASHINGTON, D. C. 20555

%..M...o February 8,1982 MEMORANDUM FOR:

H. Denton c

J. Carter D.' Eisenhut R. Purple T. Novak R. Tedesco G. Lainas H. Thompson R. Vollmer da Sniezek T. Ippolito R. Mattson THRU:

Dennis M. Crutchfield, Chief Operating Reactors Branch #5, DL FROM: :

James E. Lyons, Project Manager Operating Reactors Branch #5,.DL

SUBJECT:

DAILY HIGHLIGHT GINNA The ruptured tube in the Ginna steam generator has be.en inspected using fiber optics. The rupture has been detennided to ' start approiimately 2 to 3 inches 'above the tube sheet and is apprcAimately 5' inches long.

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The rupture is kite-shaped with a maximum width of 3/4 t6 7/8 inch.

RG&E postulates that the rupture was due to stress corrosion linked to differential expansion between the tube and the tube wrapper in the wedge region (a region where the tube support plate is fastened to the wrapper).

Profilometry, to detennine bulging or unusual shape of the.

tubes., showed some bow.ing of the tubes in the area of the rupture, thus adding credance to this theory. The ruptured tube is being plugged and removal of the tube is not anticipated due to-tts location in the tube bundle.

RG&E is planning to use fiber optics to inspect the ruptured tube from the secondary side.

Eddy current testing (ECT) of the "B" steam generator has been completed.

In addition to the ruptured tube, twenty other hot lec tubes are scheduled to be plugged.

Three of the tubes are adjacent to the ruptured tube while the others are tubes nonrelated to the accident that indcate intergranular attack (IGA) or >40% degradation. No plugging, other than the ruptured tube, e

is planned for the coTd leg of the "B" steam generator.

RG&E has commited to ECT 100% of the. "A" steam generator hot leg tubes plus all periphery tubes and a random sample of the sludge area tubes in the cold leg of the "A" steam generator.

C s

James E. Ly6ns.,

roject Manager

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Op'erating Reacto s Branch #5 h

Div'Isio'n of Licensing

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