ML051940468

From kanterella
Jump to navigation Jump to search

Duke Energy Corp, Oconee, Units 1 & 2, Mtg Summary of 6/22/05, Spring 2005 Steam Generator Inspection
ML051940468
Person / Time
Site: Oconee Duke Energy icon.png
Issue date: 07/26/2005
From:
NRC/NRR/DLPM/LPD2
To:
Duke Energy Corp
Olshan L N, NRR/DLPM, 415-1419
Shared Package
ML051940482 List:
References
TAC MC7234
Download: ML051940468 (4)


Text

July 26, 2005 LICENSEE: DUKE ENERGY CORPORATION FACILITY: OCONEE NUCLEAR STATION, UNIT 1, 2, AND 3

SUBJECT:

SUBJECT OF JUNE 22, 2005, MEETING TO DISCUSS RESULTS OF SPRING 2005 STEAM GENERATOR INSPECTION AT OCONEE NUCLEAR STATION, UNIT 1 (TAC NO. MC7234)

On June 22, 2005, the Nuclear Regulatory Commission (NRC) met with Duke Energy Corporation (the licensee) to discuss the results of the Spring 2005 steam generator inspection at Oconee Nuclear Station (Oconee), Unit 1. Attachment 1 provides a list of the attendees. contains the slides presented by the licensee during the meeting.

The steam generators at Oconee, Unit 1 were replaced during the Fall 2003 refueling outage.

This was the first replacement of once-through steam generators (i.e., steam generators with straight tubes rather than U-bend tubes).

During the 2005 steam generator tube inspections at Oconee, Unit 1, a significant number of tubes (approximately 3200) were found to have wear indications after only 14 months of operation. None of the wear indications were safety significant; however, given the large number of tubes affected, the licensee and the steam generator fabricator (B&W Canada) began a comprehensive investigation into the cause. The investigation is on-going and no single cause has been identified; however, the consensus of industry experts is that the steam generators are experiencing flow-induced wear. The excitation force for this wear is not known at this time.

The root cause investigation is expected to continue through the end of 2005. Some of the corrective actions being considered include (1) pulling tubes from Oconee, Unit 2 during its Fall 2005 outage (Oconee, Units 2 and 3 have similar replacement steam generators to those used at Oconee, Unit 1), (2) installing additional instrumentation (pressure transducers and accelerometers) on the Oconee, Unit 2 steam generators during the Fall 2005 outage, (3) and performing additional tests and analytical analysis.

The licensee has installed Nitrogen-16 monitors in each of the three units to assist in primary-to-secondary leak detection. In addition, the actions to take upon detection of primary-to-secondary leakage, including a tube rupture event, have been reviewed with the operators.

NRR and Region II continue to follow the licensees investigations.

Attachments: As stated cc w/atts: See next page

July 26, 2005 LICENSEE: DUKE ENERGY CORPORATION FACILITY: OCONEE NUCLEAR STATION, UNIT 1, 2, AND 3

SUBJECT:

SUBJECT OF JUNE 22, 2005, MEETING TO DISCUSS RESULTS OF SPRING 2005 STEAM GENERATOR INSPECTION AT OCONEE NUCLEAR STATION, UNIT 1 (TAC NO. MC7234)

On June 22, 2005, the Nuclear Regulatory Commission (NRC) met with Duke Energy Corporation (the licensee) to discuss the results of the Spring 2005 steam generator inspection at Oconee Nuclear Station (Oconee), Unit 1. Attachment 1 provides a list of the attendees. contains the slides presented by the licensee during the meeting.

The steam generators at Oconee, Unit 1 were replaced during the Fall 2003 refueling outage.

This was the first replacement of once-through steam generators (i.e., steam generators with straight tubes rather than U-bend tubes).

During the 2005 steam generator tube inspections at Oconee, Unit 1, a significant number of tubes (approximately 3200) were found to have wear indications after only 14 months of operation. None of the wear indications were safety significant; however, given the large number of tubes affected, the licensee and the steam generator fabricator (B&W Canada) began a comprehensive investigation into the cause. The investigation is on-going and no single cause has been identified; however, the consensus of industry experts is that the steam generators are experiencing flow-induced wear. The excitation force for this wear is not known at this time.

The root cause investigation is expected to continue through the end of 2005. Some of the corrective actions being considered include (1) pulling tubes from Oconee, Unit 2 during its Fall 2005 outage (Oconee, Units 2 and 3 have similar replacement steam generators to those used at Oconee, Unit 1), (2) installing additional instrumentation (pressure transducers and accelerometers) on the Oconee, Unit 2 steam generators during the Fall 2005 outage, (3) and performing additional tests and analytical analysis.

The licensee has installed Nitrogen-16 monitors in each of the three units to assist in primary-to-secondary leak detection. In addition, the actions to take upon detection of primary-to-secondary leakage, including a tube rupture event, have been reviewed with the operators.

NRR and Region II continue to follow the licensees investigations.

Attachments: As stated cc w/atts: See next page Distribution:

PUBLIC RidsRgn2MailCenter PDII-1 R/F JDavis RidsNrrPMLOlshan (Hard Copy) KKarwoski RidsOgcRP LLund RidsAcrsAcnwMailCenter MMayfield RidsNrrDlpm (LMarsh) TMintz RidsNrrDlpmLpdii (EHackett) EMurphy RidsNrrDlpmLpdii1 (EMarinos) LOlshan RidsNrrLACHawes (Hard Copy) SVias TMensah JJolicoeur Package: ML051940482 Meeting Notice: ML051580629 Attach2: ML052080113 Accession Number: ML051940468 NRC-001 OFFICE PDII-1/PM PDII-1/LA PDII-1/SC NAME LOlshan CHawes EMarinos DATE 7/26/05 7/26/05 7/26/05 OFFICIAL RECORD COPY

LIST OF ATTENDEES MEETING TO DISCUSS RESULTS OF SPRING 2005 STEAM GENERATOR INSPECTION AT OCONEE NUCLEAR STATION, UNIT 1 JUNE 22, 2005 NRC DUKE J. Davis T. Alley K. Karwoski S. Capps L. Lund G. Davenport M. Mayfield J. Davis T. Mintz R. Eaker E. Murphy D. Mayes L. Olshan M. Robinson S. Vias (by telephone)

OTHER J. Albert, B&W Canada N. Idvorian, B&W Canada R. Klarner, B&W Canada D. Lee, B&W Canada E. Bird, MPR Associates Attachment 1

Oconee Nuclear Station, Units 1, 2, and 3 cc:

Ms. Lisa F. Vaughn Ms. Karen E. Long Duke Energy Corporation Assistant Attorney General Mail Code - PB05E NC Department of Justice 422 S. Church St. P.O. Box 629 P.O. Box 1244 Raleigh, NC 27602 Charlotte, NC 28201-1244 Mr. R. L. Gill, Jr.

Ms. Anne W. Cottingham, Esq. Manager - Nuclear Regulatory Winston and Strawn LLP Issues and Industry Affairs 1700 K St, NW Duke Energy Corporation Washington, DC 20006 526 S. Church St.

Mail Stop EC05P Manager, LIS Charlotte, NC 28202 NUS Corporation 2650 McCormick Dr., 3rd Floor Mr. Richard M. Fry, Director Clearwater, FL 34619-1035 Division of Radiation Protection NC Dept of Environment, Health, & Natural Senior Resident Inspector Resources U.S. Nuclear Regulatory Commission 3825 Barrett Dr.

7812B Rochester Highway Raleigh, NC 27609-7721 Seneca, SC 29672 Mr. Peter R. Harden, IV Mr. Henry Porter, Director VP-Customer Relations and Sales Division of Radioactive Waste Management Westinghouse Electric Company Bureau of Land and Waste Management 6000 Fairview Road Dept. of Health and Env. Control 12th Floor 2600 Bull St. Charlotte, NC 28210 Columbia, SC 29201-1708 Mr. Henry Barron Mr. Michael A. Schoppman Group Vice President, Nuclear Generation Framatome ANP and Chief Nuclear Officer 1911 North Ft. Myer Dr. P.O. Box 1006-EC07H Suite 705 Charlotte, NC 28201-1006 Rosslyn, VA 22209 Mr. B. G. Davenport Regulatory Compliance Manager Oconee Nuclear Site Duke Energy Corporation ON03RC 7800 Rochester Highway Seneca, SC 29672