ML061100194
| ML061100194 | |
| Person / Time | |
|---|---|
| Site: | Oconee  |
| Issue date: | 04/25/2006 |
| From: | Olshan L Plant Licensing Branch III-2 |
| To: | |
| Olshan L N, NRR/DLPM, 415-1419 | |
| References | |
| Download: ML061100194 (5) | |
Text
April 25, 2006 LICENSEE:
DUKE ENERGY CORPORATION (DUKE)
FACILITY:
OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3
SUBJECT:
SUMMARY
OF APRIL 10, 2006, MEETING TO DISCUSS STEAM GENERATOR INSPECTION RESULTS AND ROOT CAUSE ANALYSIS On April 10, 2006, the Nuclear Regulatory Commission (NRC) met with Duke (the licensee) to update the NRC staff on the licensees continuing investigation of the root cause of the wear being observed on the steam generator (SG) tubes at Oconee Units 1 and 2. Enclosure 1 is a list of the attendees. Enclosure 2 is the slides presented by the licensee during the meeting.
Although a large number of tubes have exhibited wear, the wear has not been safety significant (i.e., the depth of the wear has been limited). This wear was observed in 2005 after just one cycle of operation following replacement of the steam generators at these units. Oconee Unit 3 will conduct its first inservice inspection of its replacement SGs in Spring 2006. The licensee has identified a number of potentially contributing factors including acoustically-induced vibration, operation at low power, higher than expected wear coefficient between the tube and the tube support plate (TSP), TSP movement, reduced contact area between the tube and TSP, and localized flow instabilities related to the geometry of the tube-to-TSP annulus.
Additional instrumentation will be installed at Unit 3 during the Spring 2006 outage and at Unit 1 during the Fall 2006 outage to assist in evaluating the root cause. The licensee expects to start reaching conclusions on the root cause by the end of the year permitting transition to corrective action.
/RA/
Leonard N. Olshan, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287
Enclosures:
- 1. List of Attendees
- 2. Licensees Handout cc w/encls: See next page
April 25, 2006 LICENSEE:
DUKE ENERGY CORPORATION (DUKE)
FACILITY:
OCONEE NUCLEAR STATION, UNITS 1, 2, AND 3
SUBJECT:
SUMMARY
OF APRIL 10, 2006, MEETING TO DISCUSS STEAM GENERATOR INSPECTION RESULTS AND ROOT CAUSE ANALYSIS On April 10, 2006, the Nuclear Regulatory Commission (NRC) met with Duke (the licensee) to update the NRC staff on the licensees continuing investigation of the root cause of the wear being observed on the steam generator (SG) tubes at Oconee Units 1 and 2. Enclosure 1 is a list of the attendees. is the slides presented by the licensee during the meeting.
Although a large number of tubes have exhibited wear, the wear has not been safety significant (i.e., the depth of the wear has been limited). This wear was observed in 2005 after just one cycle of operation following replacement of the steam generators at these units. Oconee Unit 3 will conduct its first inservice inspection of its replacement SGs in Spring 2006. The licensee has identified a number of potentially contributing factors including acoustically-induced vibration, operation at low power, higher than expected wear coefficient between the tube and the tube support plate (TSP), TSP movement, reduced contact area between the tube and TSP, and localized flow instabilities related to the geometry of the tube-to-TSP annulus. Additional instrumentation will be installed at Unit 3 during the Spring 2006 outage and at Unit 1 during the Fall 2006 outage to assist in evaluating the root cause. The licensee expects to start reaching conclusions on the root cause by the end of the year permitting transition to corrective action.
/RA/
Leonard N. Olshan, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-269, 50-270, and 50-287
Enclosures:
- 1. List of Attendees
- 2. Licensees Handout cc w/encls: See next page DISTRIBUTION:
Public RidsNrrLAMOBrien(2 copies)
KKarowski LPL2-1 r/f RidsOdcRp PKlein EMurphy RidsAcrsAcnwMailCenter TMintz RidsNrrDorlLpl2-1 RidsNrrPMLOlshan(hard copy)
EReichelt Package Accession No. ML061100211 Meeting Summary Accession No. ML061100194 NRC-001 OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA NRR/LPL2-1/BC NAME LOlshan MOBrien EMarinos DATE 4/25/06 4/25/06 4/25/06
OFFICIAL RECORD COPY LIST OF ATTENDEES MEETING TO DISCUSS STEAM GENERATOR INSPECTION RESULTS AND ROOT CAUSE ANALYSIS APRIL 10, 2006 NRC DUKE K. Karwoski R. Eaker L. Olshan J. Gilreath E. Murphy S. Capps E. Reichelt M. Robinson T. Mintz D. Mayes P. Klein T. Alley OTHER R. Klarner, Babcock & Wilcox E. Bird, MPR Associates