ML061780575
| ML061780575 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 06/23/2006 |
| From: | Jensen J Indiana Michigan Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| AEP:NRC:6055-07 | |
| Download: ML061780575 (34) | |
Text
Indiana Michigan Power INDIANA Cook Nuclear Plant MICHIGAN One Cook Place POWER
- Bridgman, MI 49106 AEP.com A unit ofAmerican Electric Power June 23, 2006 AEP:NRC:6055-07 10 CFR 50.55a Docket No:
50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Mail Stop O-PI-17 Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Unit 2 PROPOSED ALTERNATIVE TO THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS CODE, SECTION XI SUPPLEMENTAL INFORMATION
Reference:
Letter from Joseph N. Jensen, Indiana Michigan Power Company, to Nuclear Regulatory Commission Document Control Desk, 'Donald C. Cook Nuclear Plant Unit 2, Proposed Alternative to the American Society of Mechanical Engineers Code,Section XI Repair Requirements, Request for Additional Information," AEP:NRC:6055, Accession Number ML060620063, dated March 1, 2006.
The referenced letter provided Indiana Michigan Power Company's (I&M's) proposed alternative to the repair requirements of the American Society of Mechanical Engineers Code,Section XI repair requirements. I&M's alternative proposed applying preemptive weld overlays over dissimilar metal welds that connect the Donald C. Cook Nuclear Plant Unit 2 pressurizer nozzles to stainless steel safe ends. The alternative proposed the use of Code Case N-638-1 with modifications.
One modification was to perform an ultrasonic examination (UT) of the 1.5T band, a region of the nozzle adjacent to the overlay, to the extent practical.
During a March 21, 2006, telephone conversation, I&M informed Nuclear Regulatory Commission (NRC) personnel that I&M was having difficulty locating calibration blocks and fabricating new calibration blocks to meet the requirements of Code Case N-638-1 and SA-388, "Recommended Practice for Ultrasonic Testing and Inspection of Heavy Steel Forgings," a standard required to be met when following Code Case N-638-1. I&M agreed to perform a "best effort" examination, and to provide the NRC with a basis for not meeting the requirements of SA-388, and to provide updated weld schematics showing the actual amount of UT coverage obtained during the examination.
During the telephone conversation, I&M was asked to provide available information about weld-wire chemical testing following the processing of Alloy 52M billets into weld wire (Note: Thie
U. S. Nuclear Regulatory Commission AEP:NRC:6055-07 Page 2 weld wire is designated as Alloy 52MS; the "S" denotes the process used to process the billet into weld wire). The justification for the examinations performed is provided in Attachment 1. The summaries of the examinations performed are provided in Attachment 2, and the weld-wire chemical testing data are provided in Attachment 3.
This letter contains no new commitments.
Should you have any questions, please contact Ms. Susan D. Simpson, Regulatory Affairs Manager, at (269) 466-2428.
Sincerely, pl N.Jensen Site Support Services Vice President RV/rdw Attachments: 1. Preemptive Weld Overlay, Basis for Examination
- 2. Examination Summaries
- 3. Weld Wire 52MS, Certification of Chemical Overcheck Sheet c:
R. Aben - Department of Labor and Economic Growth J. L. Caldwell - NRC Region III K. D. Curry - AEP Ft. Wayne J. T. King - MPSC MDEQ - WHMD/RPMWS NRC Resident Inspector P.S. Tam - NRC Washington, DC to AEP:NRC:6055-07 PREEMPTIVE WELD OVERLAY BASIS FOR EXAMINATION The referenced letter provided Indiana Michigan Power Company's (I&M's) proposed alternative to the repair requirements of the American Society of Mechanical Engineers Code, (ASME)Section XI repair requirements. I&M's alternative proposed applying preemptive weld overlays (PWOLs) over dissimilar metal welds that connect the Donald C. Cook Nuclear Plant (CNP) Unit 2 pressurizer nozzles to stainless steel safe ends. The alternative proposed the use of Code Case N-638-1 with modifications.
One modification was to perform an ultrasonic examination (UT) of the 1.5T band, a region of the nozzle adjacent to the overlay, to the extent practical.
During a March 21, 2006, telephone conversation, I&M informed Nuclear Regulatory Commission (NRC) personnel that I&M was having difficulty locating calibration blocks and fabricating new calibration blocks to meet the requirements of N-638-1 and SA-388, "Recommended Practice for Ultrasonic Testing and Inspection of Heavy Steel Forgings," a standard required to be met when following Code Case N-638-1. I&M agreed to perform a "best.
effort" examination, and to provide the NRC with a basis for not meeting the requirements of SA-388. The basis for not meeting the requirements of SA-388 is provided below.
Code Case N-638-1 addresses the use of the temper bead welding technique. The weld overlays applied to the CNP Unit 2 pressurizer safe end to nozzle welds used this technique on the ferritic nozzle base material adjacent to the dissimilar metal welds (A-82/182 material).
The 1.5T band on the ferritic nozzle material adjacent to the PWOL is required by Code Case N-638-1 to be examined using the requirements of Appendix I of ASME Section XI, which specifies the use of ASME Section V, T-541.2.2 which states, "The calibration requirements shall be in accordance with the applicable standard listed in T-541.2."
T-541.2 requires examination to SA-388.
SA-388, Paragraph 7.3.3 states, "A separate calibration standard may be used; however, it shall have the same nominal composition, heat treatment, and thickness as the forging it represents."
Additionally, SA-388 requires that a 3 percent inside diameter (ID) and outside diameter (OD) notch be placed in the calibration block. The amplitude response from the ID notch is set at 75 percent of Full Screen Height and, with the same instrument setting, the OD notch amplitude response is identified on the screen. This establishes the reference amplitude curve for the examination. However, SA-388 is applicable to the fabrication process of the nozzle forging prior to the application of cladding on the ID of the forging.
In the case of I&M's application, the ID of the forging is clad with stainless steel which prevents the ultrasonic sound from achieving a "skip" off the cladding for examination of the OD surface.
Access to the ID is unattainable without significant and complicated disassembly and reassembly to AEP:NRC:6055-07 Page 2 of the pressurizer manway and the development of remote tooling to access the ID of each nozzle forging. Therefore, it is impractical to meet the requirements of SA-388 for a calibration block and the initial calibration and examination from the ID and OD of an installed nozzle forging with stainless steel cladding.
The UT assures that no adverse effects to the ferritic steel base material were created during the temper bead welding process.
The most likely adverse effect would be delayed hydrogen cracking, which would be initiated on the surface on which the welding was performed. For the pressurizer welds, the welding was performed on the outside surface of the ferritic nozzle.
The portion of the ferritic nozzle material below the PWOL is part of the weld overlay examination volume and was examined using performance demonstration initiative qualified ultrasonic procedures. Therefore, the presence of delayed hydrogen cracking would have been detected during the pre-service examination of the PWOL.
One-hundred percent of the pre-service examination volume was examined with no detection of any type of cracking in the PWOL examination volume.
I&M has performed a "best effort" UT of the 1.5T band from the OD using standard transducers and calibration techniques that are readily available in the industry. The examination coverages are provided in Attachment 2.
Because delayed hydrogen cracking would most likely occur at the surface of a ferritic component directly under or adjacent to the surface on which the weld is deposited, both a "best effort" UT and a liquid penetrant surface examination of the 1.5T band were performed after completion of the 48-hour hold required by Code Case N-638-1.
There were no indications observed from either the "best effort" UT or the liquid penetrant examination.
Based on these results, I&M considers the examinations of the 1.5T band to be acceptable for demonstrating that delayed hydrogen cracking did not occur as a result of the application of the temper bead welding performed to the requirements of Code Case N-638-1.
Reference:
Letter from Joseph N. Jensen, I&M, to NRC Document Control Desk, "Donald C.
Cook Nuclear Plant Unit 2, Proposed Alternative to the American Society of Mechanical Engineers Code,Section XI Repair Requirements, Request for Additional Information," AEP:NRC:6055, Accession Number ML060620063, dated March 1, 2006.
to AEP:NRC:6055-07 EXAMINATION SUMMARIES to AEP:NRC:6055-07 Page 1 Table 1 Estimated Coverage for the 1.5T Band Adjacent to Preemptive Weld Overlays Component 00 300 450 600 Estimated Volume Longitudinal 250 Shear Longitudinal 300 Shear 40 4
(Resultant (Circumferential)
(Resultant (Circumferential)
(Circumferential)
Shear Shear examined with angle 300 angle 0 angle)
(Axial)
(Axial) beams 2-PRZ-21 56%
55%
64%
N/A N/A 35%
21%
Axial 75%
Circumferential 55%
2-PRZ-22 Axial 51%
51%
N/A 37%
46%
N/A 0%*
0%*
C fial 46%
Circumferential 46%
2-PRZ-23 Axial 51%
51%
N/A 37%
46%
N/A 0%*
0%*
C fial 46%
Circumferential 46%
2-PRZ-25 51%
N/A 37%
46%
N/A 0%*
0%*
Axial 45%
Circumferential 75%
51%
N/A 37%
46%
N/A 0%*
0%*
Cicmenta 75 2-PRZ-26 Axial 98%
50%
N/A 50%
N/A 50%
59%
61%
C fial 50%
Circumferent ialol 50%
- The close proximity of the Nozzle Boss to the Preemptive Weld Overlay prevented transducer contact for 450 and 60" axial examninations to AEP:NRC:6055-07 Page 2 A
AREVA DC COOK SPRAY 2-PRZ-21 POST OVERLAY Coverage plot for Scans with 0 degree transducer 1.5T band 1.50" Coverage Estimate for 0 degree examination Total area to be examined = 2.85 in' Area able to be examined 1.61 in2 Coverage estimate = 56%
Scan area T of 0.94" is based on Spray Nozzle actual contour and thickness Figure 1 to AEP:NRC:6055-07 Page 3 A
V AIR EVA DC COOK SPRAY 2-PRZ-21 POST OVERLAY Coverage plot for Circ.
Scans with 25 degree transducer 1.5T band 1.50" Coverage Estimate for 25 degree circumferential examination Total area to be examined = 2.85 inW Area able to be examined = 1.58 in2 Coverage estimate = 55%
Scan area T of 0.94" is based on Spray Nozzle actual contour and thickness Figure 2
Page 4 to AEP:NRC:6055-07 A
AREVA DC COOK SPRAY 2-PRZ-21 POST OVERLAY Coverage plot for Scans with 30L degree transducer 1.5T band 1.50" Coverage Estimate for 30L examination Total area to be examined - 2.85 in2 Area able to be examined = 1.84 in2 Coverage estimate = 64%
Scan area T of 0.94" is based on Spray Nozzle actual contour and thickness Figure 3 to AEP:NRC:6055-07 Page 5 A
AREVA DC COOK SPRAY 2-PRZ-21 POST OVERLAY Coverage plot for axial scan with 45 degree transducer 1.5T band 1.50" Coverage Estimate for 45 degree axial examination Total area to be examined = 2.85 in2 Area able to be examined = 1.0 in3 Coverage estimate = 35%
Scan area T of 0.94" is based on Spray Nozzle actual contour and thickness Figure 4
Page 6 to AEP:NRC:6055-07 A
AREVA DC COOK SPRAY 2-PRZ-21 POST OVERLAY Coverage plot for axial scan with 60 degree transducer 1.5T band 1.50" Coverage Estimate for 60 degree axial examination Total area to be examined = 2.85 in2 Area able to be examined = 0.6 in2 Coverage estimate = 21%
Scan area T of 0.94" is based on Spray Nozzle actual contour and thickness area Figure 5 to AEP:NRC:6055-07 Page 7 A
AREVA DC COOK SAFETY 2-PRZ-22 POST OVERLAY Coverage plot for OL degree transducer Coverage Estimate for OL degree examination T of 1.32" is based on Safety/
Relief Nozzle actual contours Figure 6 to AEP:NRC:6055-07 Page 8 A A AREVA DC COOK SAFETY 2-PRZ-22 POST OVERLAY Coverage plot for 30L degree transducer 1.5T band Coverage Estimate for 30L degree examination T of 1.32" is based on Safety/
Relief Nozzle actual contours Figure 7 to AEP:NRC:6055-07 Page 9 DC COOK SAFETY 2-PRZ-22 POST OVERLAY Coverage plot for 30s degree transducer for circumferential scans AREVA Scan area on nozzle boss unable to obtain contact Coverage. Estimate for 30s degree examination Total area to be examined = 4.5 in" Area able to be examined = 2.1 in?
Coverage obtained = 46%
Overlay T of 1.32" is based on Safety/
Relief Nozzle actual contours Nozzle base material Figure 8 to AEP:NRC:6055-07 Page 10 A
AREVA DC COOK SAFETY 2-PRZ-22 POST OVERLAY Coverage plot for 45 and 60 degree transducers Scan area on nozzle boss Coverage Estimate for 45 and 60 degree axial examination Total area to be examined = 4.5 in2 Area able to be examined = 0.0 in2 Coverage obtained = 0%
T of 1.32" is based on Safety/
Relief Nozzle actual contours
'I Nozzle matei Overlay base rial DM Weld Figure 9 to AEP:NRC:6055-07 Page I11 A
AREVA DC COOK SAFETY 2-PRZ-23 POST OVERLAY Coverage plot for OL degree transducer 1.5T band Coverage Estimate for OL degree examination T of 1.32" is based on Safety/
Relief Nozzle actual contours Figure 10 to AEP:NRC:6055-07 Page 12 A
AREVA DC COOK SAFETY 2-PRZ-23 POST OVERLAY Coverage plot for 30L degree transducer 1.5T band 2.0" Coverage Estimate for 30L degree examination Total area to be examined = 4.5 in2 Area able to be examined - 1.7 in2 Coverage obtained = 37%
Overlay T of 1.32" is based on Safety/
Relief Nozzle actual contours Nozzle base material Figure 11 to AEP:NRC:6055-07 Page 13 DC COOK SAFETY 2-PRZ-23 POST OVERLAY Covdrage plot for 30s degree transducer for circumferential scans AREVA 1.5T band Scan area on nozzle boss unable to obtain contact Scan ar Safetyl
,/e
- ontours I
Coverage Estimate for 30s degree examination Total area to be examined 4.5 in2 Area able to be examined 2.1 in2 Coverage obtained = 46%
rea T of 1.32" is based on Relief Nozzle actual c r
Figure 12 to AEP:NRC:6055-07 Page 14 A
AREVA DC COOK SAFETY 2-PRZ-23 POST OVERLAY Coverage plot for 45 and 60 degree transducers I
I Scan area. on nozzle boss a on n zze boss 0 ta tact unable to obtain contact ble to b in con Coverage Estimate for 45 and 60 degree axial examination Total area to be examined = 4.5 in2 Area able to be examined = 0.0 in2 Coverage obtained = 0%
T of 1.32" is based on Safety/
Relief Nozzle actual contours Nozzle matei Overlay base rial DM Weld Figure 13 to AEP:NRC:6055-07 Page 15 A
AREVA DC COOK SAFETY 2-PRZ-24 POST OVERLAY Coverage plot for OL degree transducer 1.5T band Coverage Estimate for OL degree examination T of 1.32" is based on Safety/
Relief Nozzle actual contours Figure 14 to AEP:NRC:6055-07 Page 16 A
AREVA DC COOK SAFETY 2-PRZ-24 POST OVERLAY Coverage plot for 30L degree transducer 1.5T band 2.0" Coverage Estimate for 30L degree examination Scan area Total area to be examined = 4.5 in2 Area able to be examined = 1.7 in2 Coverage obtained = 37%
Overlay T of 1.32" is based on Safety/
Relief Nozzle actual contours Nozzle base material Figure 15 to AEP:NRC:6055-07 Page 17 A
AREVA DC COOK SAFETY 2-PRZ-24 POST OVERLAY Coverage plot for 30s degree transducer for circumferential scans 1.5T band 2.0" Coverage Estimate for 30s degree examination T of 1.32" is based on Safety/
Relief Nozzle actual contours Figure 16 to AEP:NRC:6055-07 Page 18 DC COOK SAFETY 2-PRZ-24 POST OVERLAY Coverage plot for 45 and 60 degree transducers AREVA Scan area on nozzle boss Coverage Estimate for 45 and 60 degree axial examination Total area to be examined = 4.5 in2 Area able to be examined = 0.0 in2 Coverage obtained = 0%
I T of 1.32" is based on Safety/
Relief Nozzle actual contours I __ -
Overlay Nozzle base material DM Weld Figure 17 to AEP:NRC:6055-07 Page 19 A
VA AREVA DC COOK RELIEF 2-PRZ-25 POST OVERLAY Coverage plot for OL degree transducer 1.5T band.
2.0" Scan area on nozzle boss unable to obtain contact Coverage Estimate for OL degree examination T of 1.32" is based on Safety/
Relief Nozzle actual contours Figure 18 to AEP:NRC:6055-07 Page 20 A
AREVA DC COOK RELIEF 2-PRZ-25 POST OVERLAY Coverage plot for 30L degree transducer 1.5T band Coverage. Estimate for 30L degree examination T of 1.32" is based on Safety/
Relief Nozzle actual contours Figure 19 to AEP:NRC:6055-07 Page 21 DC COOK RELIEF 2-PRZ-25 POST OVERLAY Coverage plot for 30s degree transducer for circumferential scans AREVA Coverage. Estimate for 30s degree examination T of 1.32" is based on Safety/
Relief Nozzle actual contours.
Figure 20 to AEP:NRC:6055-07 Page 22 A
AREVA DC COOK RELIEF 2-PRZ-25 POST OVERLAY Coverage plot for 45 and 60 degree transducers 1.5T band Scan-area on nozzle boss Coverage Estimate for 45 and 60 degree axial examination Total area to be examined = 4.5 in' Area able to be examined = 0.0 in2 Coverage obtained = 0%
T of 1.32" is based on Safety/
Relief Nozzle actual contours.
Nozzle matc Overlay base
- rial DM Weld Figure 21 to AEP:NRC:6055-07 Page 23 A
AREVA DC COOK SURGE NOZZLE 2-PRZ-26 POST OVERLAY Coverage plot for Scans with 0 degree transducer 1.5T band 2.375" Coverage Estimate for 0 degree examination
/1 T of 1.58" is based on Surge Nozzle contours Figure 22 to AEP:NRC:6055-07 Page 24 DC COOK SURGE NOZZLE 2-PRZ-26 POST OVERLAY Coverage plot for Scans with 30L degree transducer kkR EVA 1.5T band 2.375" Coverage Estimate for 30L degree. examination of 1.58" is based on Surge Nozzle contours Figure 23 to AEP:NRC:6055-07 Page 25 A
AREVA DC COOK SURGE NOZZLE 2-PRZ-26 POST OVERLAY Coverage plot for Circ.
Scans with 40 degree transducer 1.5T band 2.375" Coverage Estimate for 40 degree circumferential examination Scan area Total area to be examined = 7.6 in2 Area able to be examined 3.8 in2 Coverage estimate = 50%
T of 1.58" is based on.'
Nozzle contours Nozzle base material DM Weld Figure 24 to AEP:NRC:6055-07 Page 26 DC COOK SURGE NOZZLE 2-PRZ-26 POST OVERLAY Coverage plot for Scans with 45 degree transducer AREVA 1.5T band 2.375" Coverage Estimate for 45 degree examination Total area to be examined 7.6 in2 Area able. to be examined 4.5 in2 Coverage estimate = 59%
Figure 25 to AEP:NRC:6055-07 Page 27 A
A AREVA DC COOK SURGE NOZZLE 2-PRZ-26 POST OVERLAY Coverage plot for Scans with 60 degree transducer 1.5T band 2.375" Coverage. Estimate for 60 degree examination Total area to be-examined = 7.6 in2 Area able to be examined = 4.7 in2 Coverage estimate = 61%
T of 1.58" is based on Surge.
Nozzle contouts Figure 26 to AEP:NRC:6055-07 WELD WIRE 52MS CERTIFICATION OF CHEMICAL OVERCHECK SHEET
Westmorefand Mechanicaf Testing & Researc Inc.
P.O. BoX388 Westmoreland Drive Youngstown, Pa. 15696-0388 USAS.
Telephone.. 724-537-3131 Fax: 724-537-3151 c,
Website: www.wntrxcom WMT&.1is a technicaf feader in the material testing industry.
WW, Date: 02/08106 P.O. No.: 172182 WMTR REPORT NO. 6-22544 TestLog No. D10216 GARY STRAW FRAMATOME ANP 3315 OLD FOREST ROAD P.O. BOX 10935 LYNCJIBURG, VA 24506-0935 USA CERTIFICATION OF CHEMICAL OVERCHECK Page I of 1 Heat No.: NX4720TK Specimen ID: 2142-2 Analyzed Min Nickel Chromium 28.0 Manganese Silicon Carbon (Leco)
I Sulfur (Leco)
Iron 7.0 Aluminum Titanium Molybdenum Copper Niobium 0.5 Phosphorus Max Found Units REM 31.5 30.1 1.00 0.70 0.50 0.13 0.04 0.020 0.015
<0.001 11.0 8.7 1.10 0.16 1.0 0.22 0.50 0.007 0.30 0.021 1.0 0.90 0.02 0.005 0
EQUIPMENT USED:
Gases: LECO Plasma: ICPI - Plasma Emission Spectrographic SPECIFICATIONS:
Acceptable per ASME Case 2142.2 chemical requirements.
COMMENTS:
All testing done at WMT&R, Inc.
LECO analysis was performed In accordance with ASTM E1019-03 Reviewed/Approved By FANP Welding Engineering TaIS CXRrznC,.n OR REP02T 535L NO0T &Z RZ)RODU=
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N4T1-._*-004-2 Testing Specia'istsfor Aerospace, Automnotive, and Ma teria[ Testing Tields Locations in Youngstown, PA U.S.A. - Te. (724) 537-3131 and Banbury, OXyn U..K. - Tel +44 (0)12.95261211 23-9015641-000 Page 7 of 10