ML14178B419
| ML14178B419 | |
| Person / Time | |
|---|---|
| Site: | McGuire  |
| Issue date: | 07/02/2014 |
| From: | Robert Pascarelli Plant Licensing Branch II |
| To: | Capps S Duke Energy Carolinas |
| Miller G | |
| References | |
| TAC MF3850 | |
| Download: ML14178B419 (4) | |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 Mr. Steven D. Capps Vice President McGuire Nuclear Station Duke Energy Carolinas, LLC 12700 Hagers Ferry Road Huntersville, NC 28078 July 2, 2014.
SUBJECT:
MCGUIRE NUCLEAR STATION, UNIT 1 -REVIEW OF THE STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT FOR THE SPRING 2013 REFUELING OUTAGE (TAC NO. MF3850)
Dear Mr. Capps:
By letter dated July 11, 2013 (Agencywide Documents Access and Management System, (ADAMS) Accession No. ML13205A169), Duke Energy Carolinas, LLC (the licensee) submitted information summarizing the results of the 2013 Steam Generator (SG) tube inspections at the McGuire Nuclear Station, Unit No. 1. These inspections were performed during the end of cycle 22 refueling campaign. The Nuclear Regulatory Commission (NRC) staff conducted a conference call with the licensee on May 5, 2014.
The NRC staff has completed its review of the submittal and concludes that the licensee provided the information required by the McGuire 1 Technical Specifications. No additional follow up is necessary at this time. The NRC staff's review of the SG inspection report is enclosed.
If you have any questions, please contact the Project Manager, G. Edward Miller at 301-415-2481 or via e-mail at ed.miller@nrc.gov.
Docket Nos. 50-369
Enclosure:
As stated cc w/encl: Distribution via ListServ Sincerely,
- ~
Robert J. Pascarelli, Chief Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
STAFF EVALUATION BYTHE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO RESULTS OF THE 2013 STEAM GENERATOR TUBE INSPECTIONS DUKE ENERGY CAROLINAS. LLC MCGUIRE NUCLEAR STATION, UNIT 1 DOCKET NO. 50-369 By letter dated July 11, 2013 (Agencywide Documents Access and Management System, *
(ADAMS) Accession No. ML13205A169), Duke Energy Carolinas, LLC (the licensee) submitted information summarizing the results of the 2013 Steam Generator (SG) tube inspections at the McGuire Nuclear Station, Unit No. 1. These inspections were performed during the end of cycle 22 refueling campaign. The Nuclear Regulatory Commission (NRC) staff conducted a
- conference call with the licensee on May 5, 2014, to clarify portions of the report.
McGuire, Unit No. 1, has four Babcock and Wilcox International model CFR80 SGs. Each SG has 6,633 thermally treated Alloy 690 tubes, which have a nominal outside diameter of 0.688 inches and a nominal wall thickness of 0.040 inches. The tubes have an equilateral triangular pitch of 0.930 inches and the tubes were hydraulically expanded at each end for the full depth of the tubesheet. The tubesheet is 26.63 inches thick without the cladding and the tubes are welded flush to the primary face of the tubesheet. The tube support structures are lattice grids made of Type 410 stainless steel and the U-bend supports are made of Type 41 0 stainless steels.
The licensee provided the scope, extent, methods, and results of the McGuire, Unit 1, SG tube inspections in the document referenced above. In addition, the licensee described corrective actions (i.e., tube plugging) taken in response to the inspection findings.
On May 5, 2014, the licensee clarified the following during a conference call:
Visual inspections were performed of all SG channel head bowls and no degradation*
was observed.
"TWO" means through-wall depth and the use of this acronym in Section "a" of the SG Tube Inspection Report was referring to new wear indications. All new dent (DNT _and TWO indications were inspected with an array probe.
The four loose part indications (LPI) signals in SG D, as shown in Attachment 1 to the SG Tube Inspection Report, included three tubes that has loose part indications adjacent
- to the tubes and one tube where an eddy current examination did not indicate a part adjacent to the tube, but there was a possible loo,se part in an adjacent tube.
The four tubes plugged in SG D were plugged because they contained wear indications and were in the presence of a loose part that could not be removed. The plugged tubes were located in row 4, column 61 (R4C61), R6C61, R7C62, and R3C66. No visual Enclosure inspection was performed of the tubes at these locations, since the indications were at the seventh lattice grid support.
Operating Cycle 10 ended in the fall of 2008 and was 1.29 effective full power years (EFPY) in length. Operating Cycle 20 (spring 201 0) was 1.32 EFPY. Operating Cycle 21 (fall 2011) was 1.38 EFPY. Operating Cycle 22 (spring 2013) was 1.4 EFPY.
The combined EFPY for these four cycles was 5.39 EFPY.
Based on a review of the information provided in the SG Tube Inspection Report, the NRC staff concludes that the licensee provided the information required by their technical specifications.
In addition, the NRC staff concludes that there are no technical issues that warrant follow-up 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.
- ML141788419 OFFICE NRR/DORULPL2-1 /PM NRR/DORULPL2-1/LA NRR/DE/ESGB/BC NAME GEMiller SFigueroa GKulesa DATE 07/01/14 06/30/14 06/12/14