ML040850589

Summary of Steam Generator Inspection Reports from January 2002 and May 2002

ML040850589
Person / Time
Site:	Cook
Issue date:	03/31/2004
From:	Stang J NRC/NRR/DLPM/LPD3
To:	Nazar M Indiana Michigan Power Co
References
TAC MB8121, TAC MB8122
Download: ML040850589 (5)

Text

March 31, 2004 Mr. Mano K. Nazar American Electric Power Senior Vice President and Chief Nuclear Officer Indiana Michigan Power Company Nuclear Generation Group 500 Circle Drive Buchanan, MI 49107

SUBJECT:

DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 -

SUMMARY

OF STEAM GENERATOR INSPECTION REPORTS FROM JANUARY 2002 AND MAY 2002 (TAC NOS. MB8121 AND MB8122)

Dear Mr. Nazar:

By letter dated February 28, 2003, as supplemented September 15, 2003, Indiana Michigan Power Company (I&M, the licensee) submitted reports summarizing the steam generator (SG) tube inspections performed during End of Cycle (EOC) 18 (May 2002) and EOC 13 (January 2002) refueling outages for Donald C. Cook Units 1 and 2, respectively.

The Nuclear Regulatory Commission (NRC) staffs assessment of the licensees SG tube inspection reports is enclosed. The NRC staff concluded that the licensee provided the required information outlined by their Technical Specifications.

Sincerely,

/RA/

John F. Stang, Project Manager, Section 1 Project Directorate III Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-315 and 50-316

Enclosure:

NRC Staff Assessment cc w/encls: See next page

ML040850589 OFFICE PM:PD3-1 LA:PD3-1 SC:EMCB SC:PD3-1 NAME JStang THarris LLund LRaghavan DATE 03/26/04 03/26/04 03/29/04 03/30/04 Donald C. Cook Nuclear Plant, Units 1 and 2 cc:

Regional Administrator, Region III Michigan Department of Environmental U.S. Nuclear Regulatory Commission Quality 801 Warrenville Road Waste and Hazardous Materials Div.

Lisle, IL 60532-4351 Hazardous Waste & Radiological Protection Section Attorney General Nuclear Facilities Unit Department of Attorney General Constitution Hall, Lower-Level North 525 West Ottawa Street 525 West Allegan Street Lansing, MI 48913 P. O. Box 30241 Lansing, MI 48909-7741 Township Supervisor Lake Township Hall Mr. John A. Zwolinski P.O. Box 818 Director, Design Engineering and Bridgman, MI 49106 Regulatory Affairs Indiana Michigan Power Company U.S. Nuclear Regulatory Commission Nuclear Generation Group Resident Inspectors Office 500 Circle Drive 7700 Red Arrow Highway Buchanan, MI 49107 Stevensville, MI 49127 David A. Lochbaum David W. Jenkins, Esquire Union of Concerned Scientists Indiana Michigan Power Company 1616 P Street NW, Suite 310 One Cook Place Washington, DC 20036-1495 Bridgman, MI 49106 Michael J. Finissi, Plant Manager Mayor, City of Bridgman Indiana Michigan Power Company P.O. Box 366 Nuclear Generation Group Bridgman, MI 49106 One Cook Place Bridgman, MI 49106 Special Assistant to the Governor Room 1 - State Capitol Mr. Joseph N. Jensen, Site Vice President Lansing, MI 48909 Indiana Michigan Power Company Nuclear Generation Group One Cook Place Bridgman, MI 49106

SAFETY ASSESSMENT BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO

SUMMARY

OF STEAM GENERATOR INSPECTION REPORTS FROM JANUARY 2002 AND MAY 2002 INDIANA MICHIGAN POWER COMPANY DONALD C. COOK NUCLEAR PLANT, UNITS 1 AND 2 DOCKET NOS. 50-315 AND 50-316

1.0 INTRODUCTION

By letter dated February 28, 2003, as supplemented September 15, 2003, Indiana Michigan Power Company (I&M, the licensee) submitted reports summarizing the steam generator (SG) tube inspections performed during End of Cycle (EOC) 18 (May 2002) and EOC 13 (January 2002) refueling outages for Donald C. Cook (D. C. Cook) Units 1 and 2, respectively. These reports were submitted in accordance with D. C. Cook Units 1 and 2 technical specification (TS)

Sections 4.4.5.5.a, 6.9.1.4, and 6.9.1.5. A summary of the staffs evaluation of the May 2002 and January 2002 refueling outage tube inspection results is provided below.

2.0 ASSESSMENT D. C. Cook Unit 1 D. C. Cook Unit 1 has 4 SGs which are designated 11, 12, 13, and 14. All four SGs were inspected during the May 2002 refueling outage. In December 2000, the Unit 1 Westinghouse Model 51 SGs were replaced with replacement SGs consisting of Westinghouse steam domes and Babcock and Wilcox lower assembly and moisture separator units. The SGs consist of 3496 thermally-treated Inconel 690 tubes which have an outside diameter of 7/8 inch and a wall thickness of 0.049 inch. The tubes have been hydraulically expanded into the tubesheet and the SA-240-410S-modified stainless steel tube support plates (TSPs) are lattice grid type. The May 2002 refueling outage was the first in-service inspection since SG replacement.

Of particular note during the inspections, the licensee identified five manufacturing burnishing mark indications which had significant increases in the voltage amplitude (1 to 2.5 volts) since the baseline inspection. These locations were inspected with a +Point' probe and no degradation was reported at these locations. The tubes with these indications were preventively plugged.

D. C. Cook Unit 2 D. C. Cook Unit 2 has 4 SGs which are designated 21, 22, 23, and 24. All four SGs were inspected during the January 2002 refueling outage as discussed below. In 1989, the Unit 2 SGs were replaced with Westinghouse Model 54 SGs. This SG model consists of 3592 total

tubes which have an outside diameter of 7/8 inch and a wall thickness of 0.050 inch. The tubes have been hydraulically expanded into the tubesheet and the stainless steel Type 405 TSPs contain broached quatrefoil holes. The SGs have thermally-treated Inconel 690 tubes.

An eddy current inspection of the Unit 2 SGs was performed in January - February of 2002.

The base inspection scope consisted of a 50 percent full-length bobbin coil examination of the tubes in each of the four SGs. Ubends (07H-07C) of Rows 1 and 2 were not examined with the standard 720 bobbin coil probe due to potential difficulty in transversing across the low row ubends. A smaller diameter bobbin coil probe could not be used in this application as such a probe has insufficient fill factor to be qualified for that area of the tubing. As a result, a sample inspection using rotating coils was performed on 100 percent of the Row 1 and 2 in-service tubes in SG 23.

In addition, special interest examinations were performed in areas of interest using rotating probes to better characterize select bobbin coil signals. Rotating inspections were also performed in areas of interest (e.g. hot-leg top of tubesheet and in service Row 1 and 2 tubes in select SGs).

A combined total of 39 dents and 182 dings were reported using a 2-volt criterion during the bobbin coil examination. A 20 percent sample of the reported dent/ding locations was examined with a rotating coil. No degradation was detected at any of the dent/ding locations.

A total of four tubes were reported as not having a hydraulically expanded tubesheet region. SG 22 had two tubes not fully expanded in the cold-leg tubesheet while SG 23 had two tubes not fully expanded in the hot-leg tubesheet. All four tubes were examined for the full length of the tubesheet with a rotating coil. No degradation was detected in any of the non-expanded areas of these tubes.

No tubes were plugged in any of the four SGs during the 2002 Unit 2 inspection.

3.0 CONCLUSION

Based on the NRC staffs review of the information provided by the licensee, the staff concludes that the licensee provided the required information outlined by their TSs and that at this time no additional follow-up is required.

Principal Contributor: Leslie S. Miller Date: March 31, 2004