ML19305A458
| ML19305A458 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 06/08/1979 |
| From: | Herbein J METROPOLITAN EDISON CO. |
| To: | Reid R Office of Nuclear Reactor Regulation |
| References | |
| CQL-0765, CQL-765, NUDOCS 7906150324 | |
| Download: ML19305A458 (2) | |
Text
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Metropolitan Edison Company II.
J Post Office Box 542 Reading Pennsylvania 19640 215 929-3601 Writer's Direct Dial Number
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1 June 8, 1979
,i aq, 0765
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Director of Ziuclear Reactor Regulation Attn: R. W. Reid, Chief Cperating Reactors Branch !!o. k U.S. Iluelear Regulatory Cor=ission I
Washington, D.C.
20555 l
l
Dear Sir:
Three Mile Island Tiuclear Station, Unit I Operating License :To. DPR-50 Docket :!c. 50-289 Steam Generator Tube Inspection Pursuant to Technical specification 6.9.3. A(2), ve have enclosed the results of the Steam Generator Eddy Current Tube Inspections performed from February 25, 1979 to March 6, 1979, during the 1979 renteling outage.
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. Herbein Vice President L-Generatien
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Number & Extent of Tubes Inspected a.
OTSG 1A.
23.93% (3717 tubes) of the total tubes in this steam generator vere exeined at h00 kh: vith a' differential eddy current probe. All tubes were inspected for the full length from the bottom of the upper tubesheet co=pletely to the top of the lover tubesheet.
Included in this inspection vere 375 tubes which vere designated as special group A-1 as per=itted by Technical Specification h.19 2.a.k.(1) for complete inspection of the open inspection lane area.
b.
OTSG 1B.
7.075 (1,098 tubes) of the total tubes in this steam generator vere en=ined at kOO khs with a differential eddy current probe. All tubes were inspected for the full length frcm the bottom of the upper tubesheet to the top of the lower tubesheet.
Included in this inspection were 371 tubes which vere designated as special group A-1 as per=itted by Tech. Spec. h.19.2.a.k.(1) for co=plete inspection of the open inspection lane area.
2.
Locatien & Percent of Wall Thickness Penetration for Each Indication of an I= perfection a.
OTSG 1A.
Two tubes in th'is steam generator (Row 128 Tube 79 and Row 22 Tube 93) were found to contain 0.D. indications ceasured at 68".
vall thickness penetration each. The location & character of the two defect signals are believed to indicate that these are =anufacturing type defects and that they are not a result of operational degradation.
The indication in R128T79 was located at the lower side of the 15th tube suppcrt plate. The indication in R22T93 was located approximately 22 inches above the 2nd tube support plate.
In the numbering convention used the 15th tube support plate is uppernost in the OTSG. No degraded tubes were found in addition to the two cited above.
b.
OTSG 13.
No degraded tubes vere found in this steam generator.
3.
Identificatien of Sabes Plurged i
j a.
OTSG 1A.
The two defective tubes (R128T79 & R22T93) were plugged l
by explosive velding.
In additien, Rov 70 Tube 80 was plugged following an unsuccessfal atte=pt to remove a sample of this tube frcs the lower tubesheet for metallurigical & chemical analyses.
b.
0TSG 13.
No tubes were plugged in this steam generator.
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