05000336/LER-1983-020, Updated LER 83-020/01X-1:on 830613,2,557 Degraded Tubes Discovered on Steam Generator Tubing.Cause Undetermined. Tubes W/Flaws Less than + or - 40% Through Wall or Eddy Current Probe Restrications repaired.W/840213 Ltr

Updated LER 83-020/01X-1:on 830613,2,557 Degraded Tubes Discovered on Steam Generator Tubing.Cause Undetermined. Tubes W/Flaws Less than + or - 40% Through Wall or Eddy Current Probe Restrications repaired.W/840213 Ltr

ML20086N109
Person / Time
Site:	Millstone
Issue date:	02/13/1984
From:	Blanchard T, Mroczka E NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF ADMINISTRATION (ADM)
References
LER-83-020-01X, LER-83-20-1X, MP-5783, NUDOCS 8402170223
Download: ML20086N109 (2)

LER-2083-020, Updated LER 83-020/01X-1:on 830613,2,557 Degraded Tubes Discovered on Steam Generator Tubing.Cause Undetermined. Tubes W/Flaws Less than + or - 40% Through Wall or Eddy Current Probe Restrications repaired.W/840213 Ltr

Event date:
Report date:
3362083020R00 - NRC Website

text

' NRc Pecu a.s u.s NuedAa cazuLArcav Commission i7m 1 LICENSEE EVENT REPORT l

CONTROL BLOCK: l l l l l l (PLEASE PRINT G3 TYPE ALL KEZutKED INPCKuATIONS

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,7 .O I c l L6CENs48 T l MCODE l N l S l 2 l@160 l0LICENSE to l- l 0Nuw.ER l 0 l 0l 0] 0 l 7>- l 0l 0 LICENSE @3.4 TYPt l 1 Jil 1 l 1 l 1 @s7 CAT s.@

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1 oOCKET Nuustm W EVENT D ATE 74 75 MEPom7 DATE EVENT DESCR!PTION AND PROB ABLE CONSEQUENCES to o 2 lDuring scheduled inservice eddy curren examinations of steam generator tubing 2567 i

, gdegraded tubes were identified. Of these 2139 had defects > 40% through wall, 77 had _j

, gdistorted signals (DTS) and 11 tubes could not be inspected. Thus the steam j l

, ggenerators were in category C-3 of Technical Specification Table 4.4.6. This g

, constituted an abnormal degradation of the reactor coolant system pressure boundary. l

, , gSince the Unit was shutdown there was no affect on public health or safety. l o o I _

7 ..

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, stovENTiaL OCCURRENCE REPORT REVisl0N LER RO EVENTYEAR R EPORT NO. CODE TvPE No.

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47 CAUSE DESCRIPTION AND CORRECTIVE ACTIONS 27 l'_Lo_J o )3)ecific cause of the degradation lo unknown. It is characterized as suall volume l

, pits originating in the sludge pile region of the steam generator. All steam generator i tubes were inspected. All tubes with flaws > 40% through wall, DTS or eddy current Mi -

g E probe restrictions were repaired. A total of 2022 tubes were sleeved on the cold leg i i .

side I

and 192 tubes were plugged on both ends as specified in Tech. Spec. 4.4.5.1.4.b. g 1 . . .o

's**AEu? sPowen oTwERsTATus @"'sEoN a5 oiscoveny ossCainioN 022 INSERVICE INSPECTION i s W @ l0l0l0l@l " "

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.s Tom Blanchard NAME W PREPARER PHONE: (203) 447-1791 {

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O General Offices

• Seiden Street. Berlin, Connecticut n co,,,4c,,cov io., a o ,o . co. P.O. Box 270 l amem wassac.usetts eisc ac e war

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HARTFORD. CONNECTICUT 06141-0270 oar,* air uwives is a co. v (203) 666-6911 ORTe(a81 eaJCLE am to.i.OT COespasev February 13, 1984 MP-5783 U. S. Nuclear 1%gulatory Commission Document Control Desk washington, D. C. 20555

Reference:

Facility Operating License No. DPR-65 Docket No. 50-336 Reportable Occurrence RO-50-336/83-20/01X-1 Gentlemen:

This letter forwardc the Licensee Event Report 83-20/01X-1. This update repor* provides information and corrective action for the Steam Generati>r tube flaws found during inservice inspections at the end of Cycle 5. An additional three copies of the report are enclosed.

Yours truly, NORTHEAST NUCLEAR ENERGY COMPANY

/ Y #

E. J. Mroc</zka Station Superintendent Millstone Nuclear Power Station EJM/TB:ejl

Attachment:

LER 50-336/83-20/01X-1 cc: Dr. T. E. Murley, Region I Director, Office of Inspection and Enforcement Washington D.C.

Director, Office of ManageNent Information and Program Control, Washington, D.C.

V 49 i,