ML052420484

Generator In-Service Inspection Report, Unit 2, End of Cycle (EOC) 16 Response to Request for Additional Information

ML052420484
Person / Time
Site:	Mcguire
Issue date:	08/22/2005
From:	Gordon Peterson Duke Power Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
Download: ML052420484 (4)

Text

Duke GARY R. PETERSON WPower Vice President A Duke Energy Company McGuire Nuclear Station Duke Power MG01 VP / 12700 Hagers Ferry Road Huntersviyle, NC 28078-9340 704 875 5333 704 875 4809 fax grpeters@duke-energy. corn August 22, 2005 U. S. Nuclear Regulatory Commission Document Control Desk Washington, D. C. 20555-0001

Subject:

McGuire Nuclear Station Docket No. 50-370 Steam Generator In-Service Inspection Report Unit 2, End of Cycle (EOC) 16 Response to Request for Additional Information By letter dated July 7, 2005, McGuire Nuclear Station submitted the In-Service Inspection (ISI)

Outage Summary Report for McGuire Unit 2 EOC 16. This report was submitted pursuant to ASME Section XI, Paragraph IWA-6230. By facsimile dated June 14, 2005, the staff requested additional information regarding the subject report. Please find attached McGuire's response to this request.

Questions regarding this submittal should be directed to Kay Crane, McGuire Regulatory Compliance at (704) 875-4306.

Gary R. Peterson Attachment jAOGQ- 7 www. duke-energy. corn

U. S. Nuclear Regulatory Commission Document Control Desk August 22, 2005 Page 2 cc: Mr. W. D. Travers Regional Administrator, Region II U. S. Nuclear Regulatory Commission Atlanta Federal Center 61 Forsyth St., Suite 23T85 Atlanta, GA 30303 Mr. S. E. Peters NRC Senior Project Manager (MNS/CNS)

U. S. Nuclear Regulatory Commission Washington, D. C. 20555-0001 Mr. Joe Brady NRC Senior Resident Inspector (MNS)

U. S. Nuclear Regulatory Commission

Hi* 'I.T 7

,7 "! 7 REQUEST FOR ADDITIONAL INFORMATION REGARDING THE McGUIRE UNIT 2 STEAM GENERATOR TUBE INSPECTION REPORT FOR THEIR 2005 OUTAGE DOCKET NO. 50-370

1. Clarify the extent of tubes inspected. For example, were the bobbin exams full length?

Were the array probes performed full length and was all data evaluated or was the information only evaluated at expansion transitions, short radius U-bends, etc?

McGuire Response:

The bobbin coil examinations were full length and analyzed full length. The array probe quantities reported and analyzed consisted of the top of tubesheet inspection, periphery tube inspection and Special Interest inspection of bobbin indications. Other tube quantities were recorded with the array but not analyzed.

2. Please clarify what is meant by an "individual tube end repair." In Attachment 1, please clarify the difference between "SVI wear foreign object" and "VOL wear foreign object."

McGuire Response:

The term used was "inadvertent" rather than "individual" tube repair. The repair contractor routinely rolls the seal weld so the plug and stabilizer will fit the tube. The contractor rolled the wrong tubes so the tubes were repaired. SVI means that the analyst thought the tube warranted repair. VOL means that the flaw was volumetric and the analyst thought the tube did not warrant repair.

3. In Attachment #1 of your report, you identified that several tubes in steam generator (SG)

A which were plugged because of wear due to foreign objects and because of possible loose parts (PLPs). Steam generators B, C and D also have PLP indications. Please discuss whether a foreign object search and retrieval (FOSAR) was performed in each SG and whether the loose parts were removed from the steam generators. If the parts were not removed or the locations were not visually inspected, please discuss the results of any evaluations performed to ensure these parts (or suspected parts) would not result in a loss of tube integrity for the period of time between inspections.

McGuire Response:

Sludge Lancing and FOSAR was performed on all four SGs at the top of the tubesheet.

In all four SGs, parts near the periphery were visually verified to be either loose parts or sludge. Foreign objects were found in SGs 2A and 2C with some parts being removed from SG 2A. Loose parts were left in the 2A and 2C SGs. An engineering evaluation was performed to leave the parts in the 2A and 2C SGs until the next inspection cycle. In all four SGs, other PLPs were dispositioned by location (interior to the bundle at the top of the tubesheet in a low flow area or at the first lattice grid on the periphery adjacent to flow restrictor) by previous history and by engineering judgement.

4. Please discuss whether any of the wear indications currenitly left in service are a result of any other mechanism than "typical" wear (e.g., tube-to-tube contact, atypical wear, etc.)

If any indications are left inservice other than for typical wear, discuss the basis for leaving them in service (e.g., basis for growth rates).

McGuire Response:

All wear indications are a result of typical wear.

5. Please clarify how the NQIs (e.g., R 33 C122 in SG C, R14C77 and RI 15C76 in SG D; R45C1 12, R5OC1 11 and RI 18C63 in SG A) were dispositioned.

McGuire Response:

NQI's are dispositioned individually based on the results for each indication. For the examples given all but one were an NQI by bobbin and an NDF (no degradation found) by the array probe. In SG 2A for tube R1 18C63 there was NQI at 2H +2.95 inches by the bobbin coil and a VOL by the array probe. The VOL was a manufacturing burnish mark.