ML060970591
| ML060970591 | |
| Person / Time | |
|---|---|
| Site: | Harris  |
| Issue date: | 05/08/2006 |
| From: | Chandu Patel Plant Licensing Branch III-2 |
| To: | Gannon C Carolina Power & Light Co |
| Patel C, NRR/DORL/LPL2-2, 415-3025 | |
| References | |
| TAC MC8060 | |
| Download: ML060970591 (5) | |
Text
May 8, 2006 Mr. Cornelius J. Gannon, Vice President Shearon Harris Nuclear Power Plant Carolina Power & Light Company Post Office Box 165, Mail Code: Zone 1 New Hill, North Carolina 27562-0165
SUBJECT:
SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 REVIEW OF THE 2004 STEAM GENERATOR TUBE INSPECTION
SUMMARY
REPORTS (TAC NO. MC8060)
Dear Mr. Gannon:
By letters dated May 27, 2004 (Agencywide Documents Access and Management System Accession Number, ML041560343), October 28, 2004 (ML043090488), February 15, 2005 (ML050600144), August 1, 2005 (ML052210457), and February 13, 2006 (ML060530375),
Carolina Power and Light Company (the licensee) submitted information summarizing the results of its 2004 mid-cycle steam generator tube inspections at the Shearon Harris Nuclear Power Plant, Unit 1. In addition to these reports, the Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2004 steam generator tube inspections in letters dated July 26, 2004 (ML042080426) and January 12, 2005 (ML043440363).
As discussed in the enclosed evaluation, the NRC staff concludes that the licensee provided the information required by its technical specifications. In addition, the staff did not identify any technical issues that warrant followup action at this time.
Sincerely,
/RA/
Chandu P. Patel, Project Manager Plant Licensing Branch II-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-400
Enclosure:
Staff Evaluation cc w/encl: See next page
ML060970591 NRR-106 OFFICE LPL2-2/GE LPL2-2/PM LPL2-2/LA NRR/DCI LPL2-2/BC NAME SCrane CPatel RSola KKarwoski MMarshall DATE 5/5/06 5/5/06 5/3/06 5/5/06 5/8/06
Mr. C. J. Gannon, Jr.
Carolina Power & Light Company cc:
David T. Conley Associate General Counsel II -
Legal Department Progress Energy Service Company, LLC Post Office Box 1551 Raleigh, North Carolina 27602-1551 Resident Inspector/ Harris NPS c/o U. S. Nuclear Regulatory Commission 5421 Shearon Harris Road New Hill, North Carolina 27562-9998 Ms. Margaret A. Force Assistant Attorney General State of North Carolina Post Office Box 629 Raleigh, North Carolina 27602 Public Service Commission State of South Carolina Post Office Drawer 11649 Columbia, South Carolina 29211 Ms. Beverly Hall, Section Chief Division of Radiation Protection N.C. Department of Environment and Natural Resources 3825 Barrett Drive Raleigh, North Carolina 27609-7721 Mr. Chris L. Burton Manager Performance Evaluation and Regulatory Affairs PEB 7 Progress Energy Post Office Box 1551 Raleigh, North Carolina 27602-1551 Mr. Eric McCartney Plant General Manager Shearon Harris Nuclear Power Plant Carolina Power & Light Company P. O. Box 165, Mail Zone 3 New Hill, North Carolina 27562-0165 Mr. Robert J. Duncan II Director of Site Operations Shearon Harris Nuclear Power Plant Carolina Power & Light Company Post Office Box 165, Mail Zone 1 New Hill, North Carolina 27562-0165 Mr. Robert P. Gruber Executive Director Public Staff NCUC 4326 Mail Service Center Raleigh, North Carolina 27699-4326 Chairman of the North Carolina Utilities Commission Post Office Box 29510 Raleigh, North Carolina 27626-0510 Mr. Herb Council, Chair Board of County Commissioners of Wake County P. O. Box 550 Raleigh, North Carolina 27602 Mr. Tommy Emerson, Chair Board of County Commissioners of Chatham County P. O. Box 87 Pittsboro, North Carolina 27312 Mr. Christos Kamilaris, Manager Support Services Shearon Harris Nuclear Power Plant Carolina Power & Light Company P. O. Box 165, Mail Zone 1 New Hill, North Carolina 27562-0165 Mr. David H. Corlett, Supervisor Licensing/Regulatory Programs Shearon Harris Nuclear Power Plant Carolina Power & Light Company P. O. Box 165, Mail Zone 1 New Hill, NC 27562-0165 Mr. John H. ONeill, Jr.
Shaw, Pittman, Potts & Trowbridge 2300 N Street, NW.
Washington, DC 20037-1128
Enclosure EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION OF THE STEAM GENERATOR TUBE INSPECTION REPORTS FOR THE 2004 OUTAGE SHEARON HARRIS NUCLEAR POWER PLANT, UNIT 1 DOCKET NO. 50-400 By letters dated May 27, 2004 (Agencywide Documents Access and Management System Accession Number, ML041560343), October 28, 2004 (ML043090488), February 15, 2005 (ML050600144), August 1, 2005 (ML052210457), and February 13, 2006 (ML060530375),
Carolina Power and Light Company (the licensee) submitted information summarizing the results of its 2004 mid-cycle steam generator (SG) tube inspections at Shearon Harris Nuclear Power Plant, Unit 1 (Harris). In addition to these reports, the Nuclear Regulatory Commission (NRC) staff summarized additional information concerning the 2004 SG tube inspections in letters dated July 26, 2004 (ML042080426), and January 12, 2005 (ML043440363).
Harris has three Westinghouse model Delta 75 SGs, that were put into service in 2001 during refueling outage (RFO) 10. Each SG has 6307 thermally treated Alloy 690 tubes that have an outside diameter of 0.688 inch and a nominal wall thickness of 0.040 inch. The tubes were hydraulically expanded at each end for the full depth of the tubesheet. The tubes are supported by a number of stainless steel support plates that have trifoil shaped holes through which the tubes pass. Below the support plates, is a flow distribution baffle that has octafoil-shaped holes. The tubes in rows 1 through 17 (i.e., those with a bend radius less than 12 inches) received a supplemental thermal treatment (stress relieving) after bending.
The licensee provided the scope, extent, methods, and results of its SG tube inspections in the documents referenced above. The licensee also described corrective actions (e.g., tube plugging) taken in response to the inspection findings.
As a result of the review of the reports, the NRC staff has the following comments/observations:
Following a tube leak in 2004, the licensee reviewed selected eddy current data from its 2003 (RFO 11) outage. Based on this review of the 2003 data, an indication was found in the tube in row 1, column 120 of SG C. The indication was estimated by the licensee to be 37 percent through-wall. As a result, the licensee classified the SG inspection results as Category C-1 in accordance with its technical specifications. A review of the eddy current data for this indication by the NRC resulted in a depth estimate of 40 percent through-wall. A 40 percent through-wall depth estimate would have resulted in categorizing the SG as Category C-2.
In addition, the licensee classified the results of its 2004 SG tube inspections as Category C-1. This classification was made based on the results of inspections performed after plugging three tubes that were damaged by a foreign object. The estimated depths of the degradation in these three tubes were in excess of 40 percent through-wall. No classification of the inspection results was performed for the three tubes plugged during the 2004 outage. Whenever SG tube inspections are performed, the technical specifications should be used in inspecting, repairing, and classifying the results. If the three tubes mentioned above were considered in the classification, the SG inspection results would have been classified as Category C-2.
Given the staffs categorization of the inspection results, the licensee would be required by its current technical specifications to perform its next SG tube inspections within 12 to 24 calendar months from the previous inspection (May 2004). If a categorization of C-1 for the 2003 and 2004 inspections were appropriate, the licensee would be permitted to extend its inspection interval to 40 months. Since the licensee plans to perform its next SG tube inspections within 12 to 24 calendar months since its previous inspection (May 2004), the categorization of the results is less important. The next inspections are planned for RFO 13 in the spring of 2006. In addition, such categorization is no longer necessary under the new standard Technical Specifications (i.e., Technical Specification Task Force 449, Revision 4), which the licensee plans to submit for NRC approval by May 31, 2006.
During a secondary side pressure test performed in 2004, the licensee was unable to exceed a test pressure of 60 pounds per square inch gauge since the capacity of the nitrogen supply system was exceeded. Presumably, the capacity of the nitrogen supply system was exceeded as a result of a secondary side leak other than the leakage through the leaking SG tube. Based on the low levels of normal operating primary-to-secondary leakage prior to the plant shutdown, there would not appear to be any tube integrity implications associated with this possible secondary side leak. The source of the leak was never identified.
Based on a review of the information provided, the staff concludes that the licensee provided the information required by its technical specifications. In addition, the staff concludes that there are no technical issues that warrant followup action at this time since the inspections appear to be consistent with the objective of detecting potential tube degradation and the inspection results appear to be consistent with industry operating experience at similarly designed and operated units.
Principal Contributor: Kenneth J. Karwoski Date: May 8, 2006