ML20128Q026
| ML20128Q026 | |
| Person / Time | |
|---|---|
| Site: | Calvert Cliffs  |
| Issue date: | 05/28/1985 |
| From: | Lundvall A BALTIMORE GAS & ELECTRIC CO. |
| To: | Taylor J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE) |
| References | |
| NUDOCS 8506040053 | |
| Download: ML20128Q026 (4) | |
Text
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BALTIM ORE GAS AND ELECTRI CHARLES CENTER P.O. BOX 1475 BALTIMORE, MARYLAND 21203 ARTHUR E. LUNDVALL JR.
Vice PRESIDENT Suppty May 28,1985 U.S. Nuclear Regulatory Commission Office of Inspection & Enforcement Washington, DC 20555 ATTENTION:
Mr. James M. Taylor, Director
SUBJECT:
Calvert Cliffs Nuclear Power Plant Unit 1; Docket No. 50-317 Report of Steam Generator Tube Plugging
REFERENCE:
(a)
Technical Specifications, Calvert Cliffs Unit 1 ATTACHMENT:(1)
Tubes Plugged #11/#12 Steam Generator Gentlemen:
As required by Technical Specification 4.4.5.5, this letter reports the number of tubes plugged in the Calvert Cliffs Unit 1 Steam Generators during the recent May 1985 Inservice Inspection. Thirteen tubes were found to have service induced degradation which exceeded the Technical Specification plugging limit of 40% loss of nominal wall thickness, eight in #11 Steam Generator and five in #12 Steam Generator.
The number of tubes examined by Eddy Current Testing (ECT) exceeded the number required by the Calvert Cliffs Unit 1 Technical Specifications. Indications of 20% thru wall degradation or greater were found on a total of 124 tubes from the approximately 11,070 tubes examined (5,190 - #11 Steam Generator and 5,880 - #12 Steam Generator).
As stated above,13 of.these indications exceeded the plugging limit of 40% loss of nominal wall and required the tube be plugged. Additionally, six tubes which showed eddy current indications of less than 40% nominal wall loss due to degradation were also 7
plugged. The indications were all of a small volume'and small area nature.
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' Mr. hmes M. Taylor May 28,1985 Page 2 Attach'ments (1) & (2) list the tubes plugged d_uring the 1985 Unit i 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, u/
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AEL/KMH/gla Attachment cc:
- 3. A. Biddison, Esquire G. F. Trowbridge, Esquire D. H. Jaffe, NRC T. Foley, NRC d
r ATTACHMENT (1)
- 11 Steam Generator Tubes Plugged During the Unit 11985 Outage LINE -
ROW REASON FOR PLUGGING 80 138 Eddy Current Testing indication of 39% wall loss originating on the outside diameter of the tube 19.7" above the tubesheet on the cold leg side.
81 139-Eddy Current Testing indication of 63% wall loss. originating on the outside diameter of the tube 18.5" above the tubesheet on the cold leg side.
82 140 Eddy Current Testing indication of 45% wall loss originating on the outside diameter of the tube 0.4" above the tubesheet on the cold leg side.
87 75 Eddy Current Testing indication of 38% wall loss originating on the outside diameter of the tube 0.6" above the tubesheet at the hot leg side.
89 75 Eddy Current Testing indication of 52% wall loss originating on the outside diameter of the tube 0.8" above the tubesheet on the hot leg side.
91 69 Eddy Current Testing indication of 38% wall loss originating on the outside diameter of the tube 0.5" above the tubesheet on the hot leg side.
91 75 Eddy Current Testing indication of 47% wall loss originating on the outside diameter of the tube 0.8" above the tubesheet on the hot leg side.
91 73 Eddy Current Testing indication of 89% wall loss originating on the outside diameter of the tube 0.5" above the tubesheet on the hot leg side.
91 139 Eddy Current Testing indication of 78% wall loss originating on the outside diameter of the tube 20.7" above the tube-end on the hot leg side.
92 72 Eddy Current Testing indication of 63% wall loss originating on the outside diameter of the tube 1.1" above the tubesheet on the hot leg side.
4 on the outside diameter of the tube at the U-Bend A Eddy Current Testing indication of 38% wall loss origi 141 9
Eddy Current Testing indication of 50% wall loss origibating 144 62 on the outside diameter of the tube 30.9" above the #3 eggcrate support en the hot leg side.
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ATTACHMENT (2)
- 12 Steam Generator Tubes Plugged During the Unit 11985 Outage LINE ROW REASON FOR PLUGGING 27 9
Eddy Current Testing indication of 59% wall loss originating on the outside diameter of the tube at the U-Bend Apex.
43 3
Eddy Current Testing indication of 38% wall loss originating on the outside diameter of the tube 1.2" above the tubesheet on the hot leg side.
85 75 Eddy Current Testing-indication of 44% wall loss originating on the outside diameter of the tube 1.3" above the tubesheet on the hot leg side.
88 140 Eddy Current Testing indication of 57% wali loss originating on the outside diameter of the tube 20.3" above the tubesheet on the hot leg side.
94 76 Eddy Current Testing indication of 38% and 34% wall loss originating on the outside diameter of the tube 0.5" and 1.0" respectively, above the tubesheet on the hot leg side.
96-76 Eddy Current Testing indication of 45% wall loss originating on the outside diameter of the tube 0.4" above the tubesheet on the hot leg side.
l 147 85, Eddy Current Testing indication of 55% wall loss originating l
l on the outside diameter of the tube 21.7" above the #7 l
eggcrate support on the hot leg side.
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