ML080810521
| ML080810521 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 03/28/2008 |
| From: | Tam P NRC/NRR/ADRO/DORL/LPLIII-1 |
| To: | Rencheck M Indiana Michigan Power Co |
| References | |
| TAC MD5944, TAC MD5945 | |
| Download: ML080810521 (5) | |
Text
March 28, 2008 Mr. Michael W. Rencheck Senior Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106
SUBJECT:
DONALD C. COOK NUCLEAR PLANT, UNIT 1 - REVIEW OF THE STEAM GENERATOR TUBE INSERVICE INSPECTION REPORT (TAC NOS. MD5944 AND MD5945)
Dear Mr. Rencheck:
By letters dated October 31, 2006, February 27, 2007, and February 7, 2008, Indiana Michigan Power Company (I&M) submitted information pertaining to the year 2006 steam generator (SG) tube inspections at Donald C. Cook Nuclear Plant, Unit 1 (DCCNP-1). I&M performed no SG tube inspections in Unit 2 during 2006.
The Nuclear Regulatory Commission (NRC) staff has completed its review of these submittals and concludes that I&M provided the information required by the DCCNP-1 Technical Specifications and that no additional follow-up is required at this time. The NRC staffs review report is enclosed.
If you have any questions, please feel free to contact me.
Sincerely,
/RA/
Peter S. Tam, Senior Project Manager Plant Licensing Branch 3-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-315 and 50-316
Enclosure:
Staff Evaluation cc: See next page
ML080810521 OFFICE LPL3-1/PM LPL3-1/LA DE/EEEB/BC*
LPL3-1/BC NAME PTam THarris AHiser*
LJames DATE 3/25/08 3/25/08 3/11/08 3/ 28/08
- Evaluation transmitted by letter of 3/11/08.
REVIEW REPORT BY THE OFFICE OF NUCLEAR REACTOR REGULATION DONALD C. COOK NUCLEAR PLANT, UNIT 1 (DCCNP-1) 2006 STEAM GENERATOR TUBE INSERVICE INSPECTION REPORTS By letters dated October 31, 2006 (Agencywide Document Access and Management System (ADAMS) Accession No. ML063130412), and February 27, 2007 (ADAMS Accession No. ML070660516), Indiana Michigan Power Company (I&M, the licensee) submitted information pertaining to its 2006 steam generator (SG) tube inspections at DCCNP-1. No SG tube inspections were performed in Unit 2 during 2006. The licensee also provided information regarding the SG inspections in a letter dated February 7, 2008 (ADAMS Accession No. ML080510694), in response to a request for additional information by the Nuclear Regulatory Commission (NRC) staff, dated December 13, 2007 (ADAMS Accession No. ML073200204).
DCCNP-1 has 4 Model 51R recirculating SGs designed and fabricated by Babcock and Wilcox International. Each SG has 3,496 thermally-treated, Alloy 690 tubes that have an outside diameter of 0.875 inches, and a nominal wall thickness of 0.049 inches. The tubes are supported by Type 410 stainless steel, lattice-grid tube supports, and flat fan bars. The tubes were hydraulically expanded at each end for the full depth of the tubesheet.
The licensee provided the scope, extent, methods, and results of its SG tube inspections in the documents referenced above. In addition, the licensee described corrective actions (e.g., tube plugging) taken in response to the inspection findings.
After review of the information provided by the licensee, the NRC staff made the following comments/observations:
o The licensee has ceased using manual identification of tube locations during SG plugging operations to prevent reoccurrence of the process that resulted in a tube plugging error in 2002.
o Several locations were identified that had loose parts or wear attributed to loose parts.
These locations were identified through a combination of eddy current and visual inspections. Some of the loose parts were only detected through visual examination and not during the eddy current inspections. In addition, some of the loose parts were only detected with a rotating probe and not with a bobbin probe. All peripheral tubes (the locations where many of the loose parts were found) were not inspected with eddy current techniques (either with a bobbin or rotating probe). The bobbin probe detected the two largest wear signals attributed to foreign objects.
o In response to a request for additional information, the licensee indicated that it would satisfy the prescriptive inspection requirements of the Unit 1 Technical Specifications. In this response, however, the licensee did not indicate whether tube integrity would be maintained during these operating intervals (a requirement of the Technical Enclosure
Specifications). Despite the lack of a specific statement by the licensee regarding tube integrity, the NRC staff expects that the licensee has confirmed the tube integrity will be maintained for the planned operating interval between inspections. The NRC staffs expectations are based on the scope and results of the licensees inspections and operating experience at similar plants.
Based on a review of the information provided by the licensee, the NRC staff concludes that the licensee provided the information required by Unit 1s Technical Specifications. The SG tube inspections at DCCNP-1 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: Andrew B. Johnson Kenneth Karwoski Dated: March 28, 2008
Donald C. Cook Nuclear Plant, Units 1 and 2 cc:
Attorney General Department of Attorney General 525 West Ottawa Street Lansing, MI 48913 Township Supervisor Lake Township Hall P.O. Box 818 Bridgman, MI 49106 U.S. Nuclear Regulatory Commission Resident Inspector's Office 7700 Red Arrow Highway Stevensville, MI 49127 Kimberly Harshaw, Esquire Indiana Michigan Power Company One Cook Place Bridgman, MI 49106 Mayor, City of Bridgman P.O. Box 366 Bridgman, MI 49106 Special Assistant to the Governor Room 1 - State Capitol Lansing, MI 48909 James M. Petro, Jr.
Regulatory Affairs Manager Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106 Michigan Department of Environmental Quality Waste and Hazardous Materials Div.
Radiological Protection Section Radiological Assessment Unit Constitution Hall, Lower-Level North 525 West Allegan Street P. O. Box 30241 Lansing, MI 48909-7741 Joel P. Gebbie, Plant Manager Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106 Mark A. Peifer, Site Vice President Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106