ML20153F676

Special Rept:On 880818,tubes in Steam Generator Plugged in U-bend Transition Region.Caused by Stress from Tight U-bends.Unit Shut Down to Repair Tubes

ML20153F676
Person / Time
Site:	Catawba
Issue date:	09/01/1988
From:	Tucker H DUKE POWER CO.
To:	NRC OFFICE OF ADMINISTRATION & RESOURCES MANAGEMENT (ARM)
References
IEB-88-002, IEB-88-2, NUDOCS 8809070402
Download: ML20153F676 (2)

Text

- _ _ _ _ _ _ _ _ _ _ _ - . _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - . _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _

ll l

, Duke 1%er Company llu 8 herr PO Box 33198 Iice President

'* Chartone, NC 28242 Nuclear hvJaction 604)373 4511 DUKE POWER 3eptember 1,1988 Document Control Desk U. S. Nuclear Regulatory Comunission Washington, D. C. 20555

Subject:

Catawba Nuclear Station i Docket No. 50-413 Special Report Gentlemen:

Pursuant to Technical Specifications 3/4.4.5.5(a) and 6.9.2 attached is a Special Report concerning the plugging of 2 tubes in Steam Generator '1D' on August 18, 1988.

j Very truly yours,

). ls  %

Hal B. Tucker PG1J Attachment xc Dr. J. Nelson Grace, Regional Administrator U. S. Nuclear Regulatory Corunission Region II 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. P. K. Van Doorn NRC Resident Inspector Catawba Nuclear Station A

S pg 13 ,

1

o .

SPECIAL REPORT CATAWBA NUCLEAR STATION. UNIT 1 PLUGGING OF 2 TUBES IN STRAM GENERATOR 'I t On August 18, 1988, 2 tubes in Steam Generator (S/G) 1D vere plugged. Tubes 1-53 and 1-8 were plugged. Pluggable indications were found on these tubes in the U-bend transition region. The probable cause of the indications is the stress from the tight U-bends. The indications were not caused by probicas identified in NRC Bulletin 88-02. At the time Unit 1 was shutdown to repair the tubes, Reactor Coolant System leakage was well below the leakage allowed by Technical Specification 3.4.6.2.

1 I

e