ML20247E743
| ML20247E743 | |
| Person / Time | |
|---|---|
| Site: | Trojan File:Portland General Electric icon.png |
| Issue date: | 07/21/1989 |
| From: | Cockfield D PORTLAND GENERAL ELECTRIC CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NUDOCS 8907260300 | |
| Download: ML20247E743 (2) | |
Text
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- E.EGilm-dGeneralElectricCorgiinry David W. Cockfield Vice President, Nuclear July 21, 1989 Trojan Nuclear Plant Docket 50-344 License WPF-1 U.S. Nuclear Regulatory Commission ATTN: Document control Desk Washington DC 20555
Dear Sirs:
Steam Generator Tube Plugging Report During the 1989 refueling outage, an inservice inspection was conducted of all inservice tubes in all four steam generators.
In accordance with Technical Specification 4.4.5.5.a. attached is a description of the number of tubes plugged in each steam generator.
Sincerely, Attachment c: Mr.-John B. Martin Regional Administrator, Region V U.S. Nuclear Regulatory Commission Mr. David Stewart-Smith State of Oregon Department of Energy Mr. R. C. Bare g'[]
NRC Resident Inspector J
l Trojan Nuclear Plant i
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Q 121 S.W Salmon Street Portiard Oregan 97204
n, Trojan Nuclear Plant Document Control Desk Docket 50-344 July 21, 1989 License NPF-1 Attachment Page 1 of 1 STEAM GENERATOR TUBE PLUGGING During the 1989 refueling outage, an inservice inspection was conducted of all. inservice tubes in all four steam generators.
The full length of each tube was examined with a bobbin coil. Indications from the bobbin coil examination were confirmed with a motorized rotating pancake coil (MRPC).
During the confirmation process, an indication of a circumferential crack was received near the top of the tubesheet in the "B" steam generator.
The inspection program was ultimately expanded to include an MRPC examination of the upper tubesheet region on the hot-leg side of all inservice tubes in all four steam generators.
I The inspections resulted in the plugging of 245 tubes, 8 of which were stabilized prior to plugging due to circumferential crack indications.
Additionally, 82 mechanical plugs, whose heat numbers were identified in Nuclear Regulatory Commission Bulletin 89-01, " Failure of Westinghouse Steam Cenerator Tube Mechanical Plugs", were repaired through the installation.of a plug-retaining device.
The following table lists the number of tubes inspected and plugged in 1989 and the total number of tubes plugged in each steam generator.
B C
D No. of Tubes Inspected in 1989 3260 3293 3275 3252 No. of Tubes Plugged in 1989
+ for Axial Cracking 12 27 64 84
+ for Circumferential cracking 1
23 21 6
- for Ax. and Circum. Cracking 0
0 4
1
+ for Pitting 0
0 2
0
+ Total 13 50 91 91 No. of Tubes Plugged Total 141 145 204 227 RMN/SAB/LGD/bsh 3328W.0789