ML031250538
| ML031250538 | |
| Person / Time | |
|---|---|
| Site: | Vogtle  |
| Issue date: | 05/05/2003 |
| From: | Rinaldi F NRC/NRR/DLPM/LPD2 |
| To: | Gasser J Southern Nuclear Operating Co |
| Rinaldi F, NRR/DLPM/LPD2-1, 415-1447 | |
| References | |
| TAC MB6960 | |
| Download: ML031250538 (5) | |
Text
May 5, 2003 Mr. J. T. Gasser Vice President - Vogtle Project Southern Nuclear Operating Company, Inc.
Post Office Box 1295 Birmingham, Alabama 35201-1295
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNIT 1 RE: REVIEW OF STEAM GENERATOR TUBE INSERVICE INSPECTION
SUMMARY
REPORT FOR REFUELING OUTAGE 1R10 (TAC NO. MB6960)
Dear Mr. Gasser:
By letters dated April 5, and July 1, 2002, and February 12, 2003, Southern Nuclear Operating Company submitted reports and additional information addressing Nuclear Regulatory Commission (NRC) staffs questions related to the Vogtle Electric Generating Plant, Unit 1 (Vogtle-1), steam generator tube inspections performed during refueling outage 1R10 (spring 2002).
As discussed in the enclosed NRC staff review, the NRC staff has reviewed your submittals and concluded that you have provided the information required by the Technical Specifications for Vogtle-1, and no additional follow-up is required at this time. If you have any questions, contact me at (301) 415-1447.
Sincerely,
/RA/
Frank Rinaldi, Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-424
Enclosure:
As stated cc w/encl: See next page
May 5, 2003 Mr. J. T. Gasser Vice President - Vogtle Project Southern Nuclear Operating Company, Inc.
Post Office Box 1295 Birmingham, Alabama 35201-1295
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNIT 1 RE: REVIEW OF STEAM GENERATOR TUBE INSERVICE INSPECTION
SUMMARY
REPORT FOR REFUELING OUTAGE 1R10 (TAC NO. MB6960)
Dear Mr. Gasser:
By letters dated April 5, and July 1, 2002, and February 12, 2003, Southern Nuclear Operating Company submitted reports and additional information addressing Nuclear Regulatory Commission (NRC) staffs questions related to the Vogtle Electric Generating Plant, Unit 1 (Vogtle-1), steam generator tube inspections performed during refueling outage 1R10 (spring 2002).
As discussed in the enclosed NRC staff review, the NRC staff has reviewed your submittals and concluded that you have provided the information required by the Technical Specifications for Vogtle-1, and no additional follow-up is required at this time. If you have any questions, contact me at (301) 415-1447.
Sincerely,
/RA/
Frank Rinaldi, Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket No. 50-424
Enclosure:
As stated cc w/encl: See next page DISTRIBUTION:
PUBLIC BBonser, RII JNakoski CKhan FRinaldi PDII-1 R/F OGC ACRS LLund CHawes MMurphy ADAMS ACCESSION NO. ML031250538
- No significant changes to SE OFFICE PDII-1/PM PDII-1/LA EMCB*
PDII-1/SC NAME FRinaldi CHawes LLund JNakoski DATE 5/5/03 5/5/03 04/10/03 5/5/03 OFFICIAL RECORD COPY
NUCLEAR REACTOR REGULATION STAFFS REVIEW OF STEAM GENERATOR TUBE INSPECTION REPORTS SOUTHERN NUCLEAR OPERATING COMPANY, INC., ET AL.
VOGTLE ELECTRIC GENERATING PLANT, UNIT 1 DOCKET NO. 50-424 By letters dated April 5 and July 1, 2002, Southern Nuclear Operating Company (the licensee) submitted reports summarizing the steam generator tube inspections performed at the Vogtle Electric Generating Plant, Unit 1 (Vogtle-1), during refueling outage 1R10 (spring 2002). By letter dated February 12, 2003, the licensee has also provided for NRC staff review, responses to NRC questions asked during a telephone call that took place on January 13, 2003.
Vogtle-1 has four Westinghouse Model F steam generators. There are 5626 thermally treated Alloy 600 tubes in each of the steam generators. The tubes have an outside diameter of 11/16-inch, a wall thickness of 0.040-inch, and are supported by seven stainless steel tube support plates and a flow distribution baffle. The tube support plate holes are quatrefoil shaped. The U-bend region of the tubes in rows 1 through 10 were stress relieved after bending.
During refueling outage 1R10, the licensee performed tube inspections in steam generators 1 and 4. The scope and results of the inspection are discussed in the submittals provided by the licensee. Two tubes were plugged during refueling outage 1R10, since an acceptable examination could not be performed because the rotating coil probe bound and stopped rotating during the examination (i.e., encountered difficulty in passing a rotating coil probe through the U-bend region of low row tubes). Attempts were made to inspect these tubes with a 0.500-inch rotating coil probe from both the hot leg and cold leg without success. Both tubes had successfully passed a 0.520-inch bobbin coil probe during the previous inspection. The licensee believes that the binding of the rotating coil probe in the tube resulted from the differences in the design dimensions of the rotating coil and bobbin probes, and their ability to pass through the U-bend region of low row tubes.
In 1997, two tubes had also been plugged at Vogtle-1 due to "restrictions". These two tubes were plugged for what was believed to be a foreign object lodged in the tube near the U-bend region. These foreign objects are believed to be pieces of a guide tube support pin that were lodged in the tube during operation. Attempts have been made to retrieve and/or dislodge these pieces and to perform visual inspection of the loose part. However, these attempts were unsuccessful. These two tubes were inspected in the previous outage with a 0.520-inch bobbin probe.
The NRC staff concludes that the licensee has provided the information required to be submitted by the Technical Specifications and that no additional follow-up is required at this time. However, the staff notes that the licensee's explanations for the restrictions in the tubes that they plugged are plausible, but not definitive. If restrictions are found in future outages, the licensee may want to consider performing additional diagnostic examinations to investigate whether a service induced condition is causing the restrictions. For example, inspections could be performed with the largest bobbin probe that has ever passed through the tube to confirm that the rotating probe is binding and stopping because of design differences rather than due to a restriction. Similarly, profilometry of the tube in the U-bend region could confirm that the dimensions of the tube are within tolerances and visual inspections may confirm whether a loose part is lodged in a tube.
Principal Contributor: K. Karwoski, EMCB/DE Date: May 5, 2003
Vogtle Electric Generating Plant cc:
Mr. N.J. Stringfellow Manager, Licensing Southern Nuclear Operating Company, Inc.
P. O. Box 1295 Birmingham, Alabama 35201-1295 Mr.G. R. Frederick General Manager, Vogtle Electric Generating Plant Southern Nuclear Operating Company, Inc.
P. O. Box 1600 Waynesboro, Georgia 30830 Office of Planning and Budget Room 615B 270 Washington Street, SW.
Atlanta, Georgia 30334 Mr. J. D. Woodard Executive Vice President Southern Nuclear Operating Company, Inc.
P. O. Box 1295 Birmingham, Alabama 35201-1295 Steven M. Jackson Senior Engineer - Power Supply Municipal Electric Authority of Georgia 1470 Riveredge Parkway, NW.
Atlanta, Georgia 30328-4684 Mr. Reece McAlister Executive Secretary Georgia Public Service Commission 244 Washington St., S. W.
Atlanta, Ga. 30334 Harold Reheis, Director Department of Natural Resources 205 Butler Street, SE. Suite 1252 Atlanta, Georgia 30334 Attorney General Law Department 132 Judicial Building Atlanta, Georgia 30334 Mr. J. D. Sharpe Resident Manager Oglethorpe Power Corporation Alvin W. Vogtle Nuclear Plant P. O. Box 1600 Waynesboro, Georgia 30830 Charles A. Patrizia, Esquire Paul, Hastings, Janofsky & Walker 10th Floor 1299 Pennsylvania Avenue Washington, DC 20004-9500 Arthur H. Domby, Esquire Troutman Sanders NationsBank Plaza 600 Peachtree Street, NE.
Suite 5200 Atlanta, Georgia 30308-2216 Resident Inspector Vogtle Plant 8805 River Road Waynesboro, Georgia 30830 Office of the County Commissioner Burke County Commission Waynesboro, Georgia 30830