ML20111C849
| ML20111C849 | |
| Person / Time | |
|---|---|
| Site: | Beaver Valley |
| Issue date: | 05/13/1996 |
| From: | Noonan T DUQUESNE LIGHT CO. |
| To: | NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM) |
| References | |
| NPD1VPO:0473, NPD1VPO:473, NUDOCS 9605170045 | |
| Download: ML20111C849 (4) | |
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av Valley Power Station SNpptrg> ort, PA 15077 0004 THOMAS P. NOONAN (412) 393-7622 M.$,,"l"nf*"'
May 13,1996 rax (4:23 383-480s NPD1VPO:0473 United States Nuclear Regulatory Commission Document Control Desk Washington, DC 20555 Gentlemen:
Beaver Valley Power Station, Unit No.1 Docket No. 50-334, License No. DPR-66 Special Report in accordance with Appendix A, Beaver Valley Technical Specification 4.4.5.5.a, " Steam Generators", the following Special Report is submitted. This report documents the results of the Inservice inspection of steam generator tubes, performed during the Eleventh Refueling Outage.
Technical Specification 4.4 5.5.a.
On April 29, 1996, the inservice inspection of the tubing in steam generators RC-E-1 A, RC-E-1B and RC-E-1C was completed. The number of tubes inspected, and a breakdown of tubes removed from service for each steam generator, is documented in Table 1.
One hundred percent (100%) of the inservice tubes in Steam Generators RC-E-1 A,18 and 1C were examined full length with bobbin coil probes. All distorted tube support plate signals, with bobbin coil voltages >2.00 volts, were further evaluated using Rotating Pancake Coil (RPC) probes. Those signals
>2.00 volts, that were confirmed (detected) with RPC, were removed from service.
One hundred percent (100%) of the hot leg top-of-tubesheet regi-on was examined in each steam generator using the 3-coil Plus Point RPC probe. A total of two hundred thirty-two (232) tubes were removed from service for DEllVERIN.G DliAL1IY f[$k 4nnno; E'NEilCV h
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i May 13,1996 NPD1VPO:0473 Page 2 i
indications at this location.
Of this total, one (1) tube in RC-E-1A had an additional support plate indication in excess of the 2.00. volt limit that was confirmed with RPC, and four (4) tubes in RC-E-1B had circumferential i
indications that were associated with the WEXTEX transition area.
Eighteen (18) tubes with dents located at the tube support plate l
intersections, that exhibited bobbin voltages 25.00 volts, were re-examined l
using RPC. This encompassed 100% of the dents with voltages 25.00 volts and i
no indications were observed.
In addition, seventy-seven (77) tube support plate residual signals in sixty-two (62) tubes, with amplitudes large enough to mask a 1.00 volt indication, were re-examined using RPC. No indications were observed at these locations.
Three hundred forty-four (344), out of a total of four hundred forty-six (446),
candidate tubes were returned to service. All returned-to-service tubes were examiried full length with the bobbin coil probes; and, in addition, were examined with the 3-coil Plus Point RPC probe at the hot leg top-of-tubesheet region.
Sincerely, S
- ,, = d T.P.No nan Division Vice President Nuclear Operations / Plant Manager GFZ/nic Attachment i
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May 13,1996 NPD1VPO:0473 Page 3 TABLE 1 l
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3388 3388 3388 Number of tubes previously removed from service.
735 483 422 (Pre-eleventh refueling outage)
Number of tubes examined fulllength.
2653 2905 2968 (with bobbin coil probes)
)
Number of new tubes removed from service this outage.
82 110 50 (does not include de-plugged tubes)
Greater than 2.00 volt repair 1
Top-of-tubesheet distorted signals 78 103 50 Top-of-tubesheet and > 2.00 volts 1
Cold Leg Thinning 1
Row 1 U-Bend Indications 2
2 AVB Wear 4
Number of tubes de-plugged for examination.
111 125 210 (This is in addition to the full length inspections listed above for tubes which were not plugged.)
Number of tubes re-plugged.
25 37 40 Greater than 2.00 volt repair criteria 11 20 20 Top-of-tubesheet distorted signals 4
8 3
Top-of-tubesheet and >2.00 volts 2
1 AVB Wear /U-Bend 4
4 Restricted Tubes 8
4 13 Number of tubes retumed to service under the voltage-86 88 170 based repair criteria.
(These tubes examined fulllength)
Total number of tubes currently removed from service.
731 505 302 (Post eleventh refueling outage)
Percentage of tubes currently plugged.
21.58 %
14.91 %
8.91 %
A' May 13,1996 NPD1VPO:0473 Page 4 cc:
Mr. T. T. Martin, Regional Administrator United States Nuclear Regulatory Commission 4
Region 1 475 AllendaleRoad King ofPmssia, PA 19406 l
Mr. D. S. Brinkman BVPS Licensing Project Manager United States Nuclear Regulatory Commission Washington, DC 20555 l
Mr. Larry Rossbach l
BVPS Senior Resident Inspector United States Nuclear Regulatory Commission Mr. J. A. Hultz Ohio Edison Company 76 S. Main Street Akron, OH 44308 Mr. Mark Burns Centerior Energy Corporation 6200 Oak Tree Boulevard Independence, OH 44101-4661 INPO Records Center 700 Galleria Parkway Atlanta, GA 30339-5957 Mr. Robert Maiers Department ofEnvironmental Resources P.O. Box 8469 State Office Building,13th Floor Harrisburg, PA 17105-8469 Director, Safety Evaluation & Control Virginia Electric & Power Company P.O. Box 26666 One James River Plaza Richmond, VA 23261