ML063190295

American Society of Mechanical Engineers Code,Section XI Repair Requirements Preemptive Weld Overlay - Ultrasonic Examination Results

ML063190295
Person / Time
Site:	Cook
Issue date:	11/06/2006
From:	Jensen J Indiana Michigan Power Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
AEP:NRC:6055-20
Download: ML063190295 (5)

Text

Indiana Michigan Power INDIANA Cook Nuclear Plant MICHIGAN One Cook Place Bridgman, MI 49106 POWERO AERcom A unit of American Electric Power November 6, 2006 AEP:NRC:6055-20 10 CFR 50.55a Docket No.: 50-315 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop O-PI-17 Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Unit 1 AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE, SECTION XI REPAIR REQUIREMENTS PREEMPTIVE WELD OVERLAY - ULTRASONIC EXAMINATION RESULTS

Reference:

Letter from Mark A. Peifer, Indiana Michigan Power Company, to Nuclear Regulatory Commission Document Control Desk, "Donald C. Cook Nuclear Plant Unit 1, Supplement to Proposed Alternative to the American Society Of'Mechanical Engineers Code,Section XI Repair Requirements," AEP:NRC:6055-17, Accession Number ML062780203, dated September 26, 2006.

In the referenced letter, Indiana Michigan Power Company (I&M), the licensee for Donald C. Cook Nuclear Plant Unit 1, proposed an alternative to the repair requirements of the American Society of Mechanical Engineers Code,Section XI. Approval of the proposed alternative was requested to allow I&M to apply full structural preemptive weld overlays (PWOLs) on pressurizer nozzle safe-end-to-nozzle welds where NiCrFe Alloy 82/182 was originally used to weld the safe ends thereto. In requesting approval of the proposed alternative, I&M committed to providing the Nuclear Regulatory Commission with the results of the ultrasonic (UT) examinations that were performed following the application of the PWOLs. The attachment to this letter provides the results of the UT examinations.

P47?

U. S. Nuclear Regulatory Co-mmission AiEP:NRC:6055-20 Page 2 This letter contains no new commitments. Should you have any questions, please contact Ms. Susan D. Simnpson, Regulatory Affairs Manager, at (269) 466-2428.

Sincerely, N Jensen Site Support Services Vice President RGV/jen

Attachment:

Preemptive Weld Overlay Ultrasonic Examination Results c:. R. Aben - Department of Labor and Economic Growth J. L. Caldwell - NRC Region III K. D. Curry - AEP Ft. Wayne, w/o. attachmnent J. T. King - MPSC, w/o attachment MDEQ - WHMD/RPMWS, w/o attachment NRC Resident Inspector P. S. Tamn - NRC Washington DC

Attachment to AEP:NRC:6055-20 Page 2 Weld 1-PRZ-21 Overlay Indications Found: No reportable indications were identified during the UT. However, one lack-of-bond indication. was recorded at the weld overlay to nozzle material interface. The following table provides the indication parameters.

1-PRZ-21 PWOL Indication Parameters Indication Allowable Indication Allowable Weld Allowable Coverage Allowable Length, Length, Area, Area, Surface Weld Reduction Coverage inches inches* square square Area Surface due to Reduction inches inches** Percentage Area Laminar due to Percentage* Flaw, Laminar Percent Flaw, percent*

0.60 3.0 0.06 0.06 7.5 0.02 10.0 0.0 10.0 Total Total I _III

• I&M Proposed Alternative Criteria

• • Table IWB-3514-3 Criteria Disposition of Indication: The indication is within the acceptance criteria of Table IWB-3514-3 and I&M's proposed alternative.

Repairs: No repairs were performed.

Weld 1-PRZ-22 Overlay Indications Found: No reportable indications were identified during the UT.

However, one indication was noted outside of the required examination volume and was recorded for future reference. The indication is an original construction weld flaw.

Disposition of Indication: The indication is an original construction flaw that was covered by the overlay and is outside of the required examination volume. The acceptance is based on IWB-3112 (b), "Components whose volumetric or surface examination (IWB-2200) detects flaws that meet the non-destructive examination requirements of NB-2500 and

Attachment to AEP:NRC:6055-20 Page 3 NB-5300, as documented in the Quality Assurance Records, shall be acceptable' The Code Data Report, which was prepared during the fabrication of the pressurizer, documents that the pressurizer met the Code acceptance criteria.

Repairs: No repairs were performed.

Weld 1-PRZ-23 Overlay (Reexamination)

Indications Found: This weld was applied during the U1C20 outage and was re-examined after one cycle of operation. No reportable indications were identified during the UT. However, one indication was noted outside of the required examination volume. The indication was recorded during U1C20 with no changes observed during the U1C21 examination.

Disposition of Indication: The indication was determined to be acceptable following the U1C20 examination.

Repairs: No repairs were performed.

Weld 1-PRZ-24 Overlay Indications Found: No recordable indications were identified during the UT. However, four indications were noted outside of the required examination volume and were recorded for future reference. The indications are original construction flaws.

Disposition of Indications: The indications are original construction flaws that are covered by the overlay and were outside of the required examination volume. The acceptance is based on IWB-3112 (b), "Components whose volumetric or surface examination (IWB-2200) detects flaws that meet the non-destructive examination requirements of NB-2500 and NB-5300, as documented in the Quality Assurance Records, shall be acceptable' The Code Data Report, which was prepared during the fabrication of the pressurizer, documents that the pressurizer met the Code acceptance criteria.

Repairs: No repairs were performed.

Attachment to AEP:NRC:6055-20 Page4 Weld 1-PRZ-25 Overlay Indications Found: No reportable indications were identified during the UT. However, seven lack-of-bond indications were recorded between the original nozzle surface and the overlay weld. The following table provides the indication parameters.

l-PRZ-25 PWOL Indication Paramneters Indication Allowable Indication Allowable Weld Allowable Coverage Allowable Length, Length, Axea, Area, Surface Weld Reduction Coverage inches inches* square square Area Surface due to Reduction inches inches** Percentage Area Laminar due to Percentage* Flaw, Laminar percent Flaw, percent*

0.66 3.0 0.132 0.60 3.0 0.120 1.09 3.0 0.218 2.02 3.0 0.404 2.14 3.0 0.428 0.91 3.0 0.182 0.55 3.0 0.110 1.594 7.5 Total 0.296 10.0 0.0 10.0 Total I

• I&M Proposed Alternative Criteria

• • Table IWB-3514-3 Criteria Disposition of Indications: The indications are within the acceptance criteria of Table IWB-3514-3 and I&M's proposed alternative.

Repairs: No repairs were performed.

Reference Letter from Mark A. Peifer, Indiana Michigan Power Company, to Nuclear Regulatory Commission Document Control Desk, "Donald C. Cook Nuclear Plant Unit 1, Supplement to Proposed Alternative to the American Society Of Mechanical Engineers Code,Section XI Repair Requirements," AEP:NRC:6055-17, Accession Number ML062780203, dated September 26, 2006.