ML20216K117
| ML20216K117 | |
| Person / Time | |
|---|---|
| Site: | Vermont Yankee File:NorthStar Vermont Yankee icon.png |
| Issue date: | 07/03/1978 |
| From: | Klinger G, Nolan F, Whitt K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| To: | |
| References | |
| PNO-78-130, NUDOCS 9804220097 | |
| Download: ML20216K117 (1) | |
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PRELIMINARY NOTIFICATION July 3, 1978 l
PRFLIMINARY NOTIFICATION OF EVENT OR UNUSUAL OCCURRENCE--PNO-78-130 This preliminary notification constitutes EARLY notice of an event of POSSIBLE safety or public interest significance.
The information I
presented is as initially recei_ved without verification or evaluation
_and is basically all that is known by IE staff on this date.
Facility:
Vermont Yankee Nuclear Power Corporation Vermont Yankee (DN 50-271)
Vernon, Vermont a
Subject:
CRACK IN TORUS On June 28, 1978, five non-penetrating surface crack indications and one 9-inch long surface crack were identified on the torus in the heat affected l
zone of welding which was being performed as a part of a modification, adding strengthening gussets to the torus support columns.
Following i
minimum torus wall thickness analysis, plans were made to grind out the 9-inch crad.
On June 30, 1978, after grinding out the crack to the i
calculated Jepth, the crack was found to be still deeper.
The plant was
~~ '
m.
placed in a cold shutdown condition on July 2.
Licensee evaluation is in progress.
Nominal torus wall thickness is 0.597 inches, and minimum wall thickness is 0.3 inches.
The crack was ground to 0.25 inches (0.347 inch wall thickness) when shutdown was initiated.
No additional grinding will be conducted until the problem has been reviewed by the licensee.
Additional Liquid Penetrant Testing is in progress.
Media interest is expected.
The State of Vermont has been informed.
A press release is planned by the licensee.
i NRC, Region I, (Philadelphia) received notification of this occurrence by telephone from Plant Superintendent at 4:40 a.m., July 1,1978.
Contact:
GKlingler, IE x28019 FNolan, IE x28019 KWhitt, IE x28019 i
Distribution:
Transmitted H St1: Q/
Chairman Hendrie Commissioner Bradford i
~
t Commissioner Kennedy S. J. Chilk, SECY C. C. Kammerer, CA 1
Commissioner Gilinsky (For Distribution)
I Transmitted:
MNBB /; h P Bldg /l V Y E. Volgenau, IE L. V. Gossick, EDO E. G. Case, NRR Region._L-
// Y9 S. H. Hanauer, EDO J. J. Fouchard, PA' SS Bldg /! N (MAIL)
'i N. M. Haller, MPA C
! 3. V. Smith, NMSS
f hU 9804220097 780703 PDR I&E PNO-78-130 PDR l
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