ML043130438
| ML043130438 | |
| Person / Time | |
|---|---|
| Site: | Catawba  |
| Issue date: | 11/11/2004 |
| From: | Sean Peters NRC/NRR/DLPM/LPD1 |
| To: | Jamil D Duke Energy Corp |
| Peters S, NRR/DLPM, 415-1842 | |
| References | |
| TAC MC4503 | |
| Download: ML043130438 (6) | |
Text
November 11, 2004 Mr. D. M. Jamil Vice President Catawba Nuclear Station Duke Energy Corporation 4800 Concord Road York, SC 29745
SUBJECT:
CATAWBA NUCLEAR STATION, UNIT 2 RE:
SUMMARY
OF CONFERENCE CALL REGARDING THE 2004 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. MC4503)
Dear Mr. Jamil:
On September 27, 2004, the U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with Duke Energy Corporation, the licensee for Catawba Nuclear Station, Unit 2 regarding the 2004 steam generator (SG) tube inspection activities. The NRC staffs summary of the conference call is enclosed.
The NRC staff also plans to review the Catawba, Unit 2 SG inspection summary reports when submitted according to the Technical Specification requirements. If you have any questions concerning this matter, please contact me at (301) 415-1842.
Sincerely,
/RA/
Sean E. Peters, Project Manager, Section 1 Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-414
Enclosure:
Summary of Conference Call cc w/encl: See next page
November 11, 2004 Mr. D. M. Jamil Vice President Catawba Nuclear Station Duke Energy Corporation 4800 Concord Road York, SC 29745
SUBJECT:
CATAWBA NUCLEAR STATION, UNIT 2 RE:
SUMMARY
OF CONFERENCE CALL REGARDING THE 2004 STEAM GENERATOR TUBE INSPECTIONS (TAC NO. MC4503)
Dear Mr. Jamil:
On September 27, 2004, the U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with Duke Energy Corporation, the licensee for Catawba Nuclear Station, Unit 2 regarding the 2004 steam generator (SG) tube inspection activities. The NRC staffs summary of the conference call is enclosed.
The NRC staff also plans to review the Catawba, Unit 2 SG inspection summary reports when submitted according to the Technical Specification requirements. If you have any questions concerning this matter, please contact me at (301) 415-1842.
Sincerely,
/RA/
Sean E. Peters, Project Manager, Section 1 Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-414
Enclosure:
Summary of Conference Call cc w/encl: See next page DISTRIBUTION:
PUBLIC PDII-1 R/F MRoss-Lee DClarke SPeters OGC ACRS LLund MMurphy MErnestes, RII MLesser, RII ADAMS Accession Number: ML043130438 OFFICE PDII-1/PM PDII-1/LA (A)
PDII-1/SC (A)
NAME SPeters DClarke MRoss-Lee DATE 11/10/04 11/12/04 11/11/04 OFFICIAL RECORD COPY
Catawba Nuclear Station, Units 1 & 2 Page 1 of 2 cc:
Mr. Lee Keller, Manager Regulatory Compliance Duke Energy Corporation 4800 Concord Road York, South Carolina 29745 Ms. Lisa F. Vaughn Duke Energy Corporation Mail Code - PB05E 422 South Church Street P.O. Box 1244 Charlotte, North Carolina 28201-1244 Ms. Anne Cottingham, Esquire Winston and Strawn 1400 L Street, NW Washington, DC 20005 North Carolina Municipal Power Agency Number 1 1427 Meadowwood Boulevard P.O. Box 29513 Raleigh, North Carolina 27626 County Manager of York County York County Courthouse York, South Carolina 29745 Piedmont Municipal Power Agency 121 Village Drive Greer, South Carolina 29651 Ms. Karen E. Long Assistant Attorney General North Carolina Department of Justice P.O. Box 629 Raleigh, North Carolina 27602 NCEM REP Program Manager 4713 Mail Service Center Raleigh, North Carolina 27699-4713 North Carolina Electric Membership Corp.
P.O. Box 27306 Raleigh, North Carolina 27611 Senior Resident Inspector U.S. Nuclear Regulatory Commission 4830 Concord Road York, South Carolina 29745 Mr. Henry Porter, Assistant Director Division of Waste Management Bureau of Land and Waste Management Dept. of Health and Environmental Control 2600 Bull Street Columbia, South Carolina 29201-1708 Mr. R.L. Gill, Jr., Manager Nuclear Regulatory Issues and Industry Affairs Duke Energy Corporation 526 South Church Street Mail Stop EC05P Charlotte, North Carolina 28202 Saluda River Electric P.O. Box 929 Laurens, South Carolina 29360 Mr. Peter R. Harden, IV, Vice President Customer Relations and Sales Westinghouse Electric Company 6000 Fairview Road 12th Floor Charlotte, North Carolina 28210 Ms. Mary Olson Director of the Southeast Office Nuclear Information and Resource Service 729 Haywood Road, 1-A P.O. Box 7586 Asheville, North Carolina 28802
Catawba Nuclear Station, Units 1 & 2 Page 2 of 2 cc:
Mr. T. Richard Puryear Owners Group (NCEMC)
Duke Energy Corporation 4800 Concord Road York, South Carolina 29745 Mr. Richard M. Fry, Director Division of Radiation Protection NC Dept. of Environment, Health, and Natural Resources 3825 Barrett Drive Raleigh, North Carolina 27609-7721 Mr. Henry Barron Group Vice President, Nuclear Generation and Chief Nuclear Officer P.O. Box 1006-EC07H Charlotte, NC 28201-1006 Diane Curran Harmon, Curran, Spielbergy &
Eisenberg, LLP 1726 M Street, NW Suite 600 Washington, DC 20036
ENCLOSURE DUKE ENERGY CORPORATION NORTH CAROLINA MUNICIPAL POWER AGENCY NO. 1 PIEDMONT MUNICIPAL POWER AGENCY DOCKET NO. 50-414 CATAWBA NUCLEAR STATION, UNIT 2 SEPTEMBER 27, 2004 CONFERENCE CALL
SUMMARY
2004 STEAM GENERATOR TUBE INSPECTIONS On September 27, 2004, the U.S. Nuclear Regulatory Commission (NRC) staff participated in a conference call with Duke Energy Corporation (Duke), the licensee for Catawba Nuclear Station (Catawba), Unit 2 to discuss selected plans and results of the 2004 steam generator (SG) tube inspections.
Catawba, Unit 2 has four Westinghouse Model D5 SGs. Each SG contains 4,570 thermally treated Alloy 600 tubes with an outside diameter of 0.750 inch and a nominal wall thickness of 0.043 inch. The tubes are hydraulically expanded for the full depth of the tubesheet at each end.
The licensees initial plans included inspecting the full length of approximately 50 percent of the tubes in each of the four SGs with a bobbin coil. The bobbin coil was also used to inspect certain special interest tubes which would increase the overall scope to approximately 55 percent of the tubes. In addition to the bobbin coil inspections, the licensee planned to use a rotating probe to inspect the hot-leg expansion transition region in approximately 25 percent of the tubes in each of the SGs. These inspections were to be from 2 inches above the top of the tubesheet to 9 inches below the top of the tubesheet.
During the rotating probe examinations in the tubesheet region in SG B, the licensee found two discrete circumferential indications in an overexpanded region of one tube. The location of the indications was approximately 7.59 inches below the top of the hot leg tubesheet. The indications initiated from the inside diameter of the tubes, and are approximately 30 degrees in circumferential extent. The overexpanded region extended for approximately 6 inches and the diameter was estimated to be approximately 0.004 inch greater than that observed in the remainder of the expanded region. Overexpansions in the tubesheet region are a result of expanding the tube into a region of the tubesheet which is not perfectly round. This condition is a result of anomalies in the tubesheet drilling process (e.g., drill-bit wandering). As a result of identifying these two circumferential indications, Duke increased the scope of the rotating probe examinations in the tubesheet region to include all tubes with overexpanded regions in the hot-leg. The licensee inspected these tubes from 2 inches above the top of the tubesheet to the tube-end. There are approximately 1300 tubes in the hot-leg tubesheet region which have overexpanded regions.
At the time of the conference call, Duke completed approximately 95 to 98 percent of these additional rotating probe examinations. No additional indications were found in the overexpanded regions; however, several indications were found at the tube ends and one indication was found in the tack roll region. At the tube-ends, the licensee identified approximately 12 indications. Duke found these indications in SGs A, B, and D and they are in the tube-to-tubesheet weld. Initial visual inspections of the weld did not result in the identification of the flaws. The indication in the tack roll (the region of the tube roll expanded into the tubesheet to facilitate welding) was approximately 0.75 inch above the tube-to-tubesheet weld and was circumferentially oriented. It was estimated to be 330 degrees in circumferential extent and 100 percent through-wall. The orientation and size of the indications in the tube end were not discussed.
Based on these results, the licensee indicated that they were considering expanding the scope of the rotating probe examinations in the tubesheet region to include inspecting 100 percent of the tubes in SG B and 20 percent of the tubes in SGs A, C, and D from 2 inches above the top of the tubesheet to the tube-end. These additional examinations were estimated to take approximately 4 to 5 days.
The licensee planned to plug the tube with the circumferential indication in the overexpanded region and the tube with the circumferential indication in the tack roll. The NRC staff indicated that if the tube end indications are in the tube-to-tubesheet weld, the evaluation and repair of these flaws should be consistent with the requirements in the American Society of Mechanical Engineers Boiler and Pressure Vessel Code.
The licensee indicated they would inform the NRC staff if any additional indications were identified.
Subsequent to the call, the licensee informed the NRC staff that it would be expanding the scope of the rotating probe examination in the tubesheet region to include inspecting 100 percent of the tubes in SG B and 20 percent of the tubes in SGs A, C, and D from the tube-end through the tack roll region (approximately 2 to 3 inches from the tube-end). This scope would include the regions where crack-like indications were found during the rotating probe examinations of the overexpanded tubes.