ML20006F863

Provides Steam Generator Tube Plugging & Sleeving Info,Per Tech Spec 4.12.E.1.Following Recent Inservice insp,15 Tubes Plugged for First Time & 37 Tubes W/New Indications Sleeved

ML20006F863
Person / Time
Site:	Prairie Island
Issue date:	02/22/1990
From:	Parker T NORTHERN STATES POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
NUDOCS 9003010281
Download: ML20006F863 (3)

Text

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414 Nicollet Mall Minneapolis. Minnesota $54011927 .

Telephone (612) 3D$500 i

February 22, 1990 Technical Specification 4.12.E.1 l l

Director of Nuclear Reactor Regulation i

U S Nuclear Regulatory Commission  ;

' Attn: Document Control Desk '

Washington, DC 20555 i

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[' PRAIRIE ISLAND NUCLEAR CENERATING PLANT {

Docket Nos. 50 282 License Nos. DPR 42 i

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50 306 DPR 60 Steam Generator Tube Pluccinc and Sleevinc In accordance with Technical Specification 4.12 E.1, the following steam i generator tube plugging and sleeving information is provided for the ,

information of the NRC staff.

Following the recent inservice inspection of the Unit 1 steam generators, l

. fifteen tubes were plugged for the first time and thirty seven tubes with new  !

indications were sleeved. The percentage of tubes plugged is 2.13% on steam ,

generator 11. The percentage of tubes plugged and sleeved equivalent is 1.87%

on steam generator 12. A summary is attached.

This information will be expanded upon in the Inservice Inspection Report for ,

Unit I which will be submitted within 90 days of the end of the current i refueling outage. Also Table 4.3 14 of the Prairie Island Updated Safety Analysis Report will be updated in the next revision.

If you have any questions concerning this information please call. .

1 Thomas M Parker Manager Nuclear Support-Services L. c

Regional Administrator Region III, NRC

); Senior Resident Inspector, NRC ,

NRR Project Manager, NRC G Charnoff

Attachment:

Steam Generator Tube Plugging / Sleeving Summary l i

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, STEAM GENERATOR TURE PLUCCING/ SLEEVING

SUMMARY

I -Steam'Cenerator.No.11 Summary n ,>

New Indications Plugged This Outage: 3 g/ Total Tubes Plugged: 72-Total Tubes Sleeved: 0:

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[ 11: Steam Generator t Plugged: 2.13%

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Plug Removal: 15 plugs removed and replaced, b<

g .New Indicati g Three tubes were plugged for thinning at the cold leg tube support

' plate. -

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-Tube Plum Removal:-

e Fifteen plugs were removed due to susceptibility to primary water stress-corrosion cracking.' Ten plugs were required to be removed by NRC Bulletin 89 01.

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Two tubes were replugged with Combustion Engineering welded tube plugs.-

The'other 13 were replugged with Westinghouse Alloy 690 mechanical

-plugs.

h Steam Generator No' 12 Summary New1 Indications-Plugged This Outage: 12-ii New Indications Sleeved This Outage:' 37 ~

Tubes' Returned to Service: -1 a' ~ Tubes' Returned to Service by Sleeving: 26.

Total Tubes Plugged

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56-Total Sleeves Installed and-In Service: -163 4

12 Steam Generator % Plugged +

t Sleeved' Equivalent: 1.874

-New Indications!-

E Forty nine defective tubes were identified:

Seven tutes were plugged for. thinning at cold leg tube support plates.

One tube was plugged-for an indication at a hot leg support plate.

Thirty seven tubes were sleeved for defects in the hot leg tubesheet region.

0 Four tubes were. plugged for defects in the hot leg tubesheet region in-areas where sleeves cannot be installed.

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. Tube Plug Removal; i 6

Eighty one plugs were removed in order'to return the tubes to service f l' .11 -and/or to remove plugs susceptible to primary water stress corrosion .

cracking. Thirty six plugs were required to be removed by NRC Bulletin '

89-01. Twenty six tubes were returned to service by sleeving. One tube was returned to service by reevaluation of the original defect. . Six tubes were replugged with Combustion Engineering welded tube plugs. Tho'

. remaining eighteen were replugged with Westin5house Alloy 690 mechanical

, plugs. . Note: Not all tubes replugged had the original plugs removed from both ends of the tubes.

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