ML20092A749

Forwards Listing of Number of Tubes Plugged in Steam Generators 21 & 22 During 1984 Refueling Outage W/Reasons for Plugging.Six Tubes Discovered W/Indications Requiring Plugging

ML20092A749
Person / Time
Site:	Calvert Cliffs
Issue date:	06/14/1984
From:	Lundvall A BALTIMORE GAS & ELECTRIC CO.
To:	Deyoung R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE)
References
NUDOCS 8406190341
Download: ML20092A749 (3)

Text

.

BALTIMORE GAS AND ELECTRIC CHARLES CENTER P.O. BOX 1475 BALTIMORE, MARYLAND 21203 ARTH U R E. LUN DVALL, JR.

Vict Poetsiotnet SuPPLv June 14,1984 U.S. Nuclear Regulatory Commission Office of Inspection & Enforcement Washington, DC 20555 ATTENTION:

Mr. Richard C. DeYoung, Director

SUBJECT:

Calvert Cliffs Nuclear Power Plant Unit 2; Docket No. 50-318 Report of Steam Generator Tube Plugging

REFERENCE:

(a)

Technical Specifications, Calvert Cliffs Unit 2 ATTACHMENT:(1)

Tuoes Plugged #21/#22 Steam Generator Gentlemen:

As required by Technical Specificatier. 4.4.5.5, this letter reports the number of tubes plugged in the Calvert Cliffs Unt 2 Steam Ger.erators during the recent May 1984 Inservice Inspection. Six tubes were found to have service induced degradation which exceeded the Technical Specification plugging limit of bJ% Ms of nominal wall thickness, four in #21 Steam Generator and two in #22 Steam Generator. These six tubes were removed from service by plugging the hot and cold leg tube ends with mechanical tube plugs.

The number of tubes examined by Eddy Current Testing exceeded the requirements of the Calvert Cliffs Unit 2 Technical Specifications. Indications were found on a total of 50 tubes from the approximately 13,800 tubes examined (7,300 #21 steam generator and 6,500 #22 steam generator). As stated above, six of these indications exceeded the plugging limit of 40% loss of noininal wall and required the tube be plugged. The indications were all of a small volume and small area nature.

8406190341 B40614 PDR ADOCK 05000318 G

PDR I

Mr. Richard C. DeYoung June 14,1984 Page 2 Attachment (1) lists the tubes plugged during the 1984 Unit 2 Refueling Outage along with the reason for plugging the tube. Should you have further questions regarding this matter, please do not hesitate to contact us.

Very truly yours, f,

M<vh

/

' AEL/KMH/gla Attachment cc D. A. Brune, Esquire G. F. Trowbridge, Esquire D. H. Jaf fe, NRC T. Foley, NRC

ATTACHMENT (1)

1. 21 Steam Generator Tubes Plugged During the Unit 21984 Outage LINE ROW REASON FOR PLUGGING i

52 128 Eddy Current Testing indication of 81% and 52% wall loss originating on the outside diameter of the tube 14.9" and 14.2" above the tubesheet on the hot leg side.

34 38 Eddy Current Testing indication of 53% wall loss originating on the outside diameter of the tube 1.8" above the tubesheet on the hot leg side.

144 22 Eddy Current Testing indication of 49% wall loss originating on the outside diameter of the tube 1.1" above the tubesheet hot leg side.

132 2

Eddy Current Testing indication of 53% wall loss originating on the outside diameter of the tube 12.7" above the #5 eggcrate support on tha cold leg side.

i

1. 22 Steam Generator Tubes Plugged During the Unit 21984 Outage LINE ROW REASON FOR PLUGGING 97 81 Eddy Current Testing indication of 61% wali loss originating on the outside diameter of the tube 1.8" above the tubesheet on the hot leg side.

91 35 Eddy Current Testing indication of 56% wail loss originating on the outside diameter of the tube at the

1. 5 batwing support.

k i

?

--+~v m

p,,-,