ML070390047
| ML070390047 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 01/26/2007 |
| From: | Jensen J Indiana Michigan Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| AEP:NRC:7055-01, MRP-139 | |
| Download: ML070390047 (5) | |
Text
Indiana Michigan Power INDIANA Cook Nuclear Plant MICHIGAN One Cook Place Bridgman, MI 49105 AEPcom A unit of American Electric Power January 26, 2007 AEP:NRC:7055-01 Docket Nos.: 50-315 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 Units I and 2 Inspection and Mitigation of Alloy 82/182 Pressurizer Butt Welds In October of 2006, while performing inspections of its pressurizer Alloy 82/182 butt welds in accordance with MRP-139, a pressurized water reactor licensee discovered several circumferential indications in its pressurizer surge, safety, and relief nozzles. Because of the potential importance of this issue, Indiana Michigan Power Company (I&M) is writing this letter to document actions taken to mitigate Alloy 82/182 weld concerns on pressurizer spray, surge, and relief lines at Donald C. Cook Nuclear Plant (CNP) Units I and 2.
I&M has mitigated pressurizer Alloy 82/182 weld concerns by applying weld overlays on dissimilar metal welds. Details concerning the specific locations where overlays were applied are included in the attached tables.
Future inspections of pressurizer butt welds at CNP will be performed in accordance with industry guidance (MRP-139).
This letter contains no new commitments.
Should you have any questions, please contact Ms. Susan D. Simpson, Regulatory Affairs Manager, at (269) 466-2428.
RGV/rdw
Attachment:
Pressurizer Alloy 82/182 Butt Weld Mitigation Summary ArIlD
U. S. Nuclear Regulatory Commission Page 2 c:
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 AEP:NRC:7055-01
Attachment to AEP:NRC:7055-01 Pressurizer Alloy 82/182 Butt Weld Mitigation Summary
Attachment to AEP:NRC:7055-01 Page I Table 1 Inspection and Mitigation Summary for Alloy 82/182 Pressurizer Butt Welds Unit 1 MRP-139 Volumetric Mitigation Nozzle Inspection Requirement Completed Met Susceptible Outage Start Date Outage Function/Designation Material Description Designation (Month/Year))
Designation A Performance Demonstration Spray Nozzle to safe U1C21 9/2006 U1C21 Initiative (PDI) qualified (Weld 1-PRZ-24) end weld inspection was performed after the overlay was applied.
Surge Nozzle to safe A PDI qualified inspection was (Weld 1-PRZ-25) end weld U1C21 9/2006 UIC21 performed after the overlay was applied.
A flaw was identified using a best effort ultrasonic Safety A Nozzle to safe bs fot utaoi Saety A-PNozzle tosafe U1C20 3/2005 UIC20 examination.
A PDI qualified inspection was performed after the overlay was applied.
Safety B Nozzle to safe A PDI qualified inspection was Safety B Nozzlen to sa U1C21 9/2006 UIC21 performed after the overlay was (Weld 1-PRZ-22) end weld applied.
Safety C Nozzle to safe A PDI qualified inspection was (Weld t-PRZ-21) end weld U1C21 9/2006 UIC21 performed after the overlay was applied.
Relief Nozzle to safe A PDI qualified inspection was (Weld 1-PRZ-20) end weld U1C21 9/2006 UIC21 performed after the overlay was (Weld__-PRZ-20)_
endweld applied.
Attachment to AEP:NRC:7055-01 Page 2 Table 2 Inspection and Mitigation Summary for Alloy 82/182 Pressurizer Butt Welds Unit 2 MRP-139 Volumetric Mitigation Nozzle Inspection Requirement Completed Comments Met Susceptible Outage Start Date Outage Function/Designation Material Description Designation (Month/Year)
Designation Spray Nozzle to safe A PDI qualified inspection was Spray end weld with U2C16 3/2006 U2C16 performed after the overlay was (Weld 2-PRZ-21) buttering applied.
Surge Nozzle to safe A PDI qualified inspection was (Weld 2PRZ26) end weld with U2C16 3/2006 U2C16 performed after the overlay was buttering applied.
Nozzle to safe A PDI qualified inspection was (Weld2-PRZ-24) end weld with U2C16 3/2006 U2C16 performed after the overlay was
(
buttering applied.
Safety B Nozzle to safe A PDJ qualified inspection was end weld with U2C16 3/2006 U2C16 performed after the overlay was buttering applied.
Safety C Nozzle to safe A PDI qualified inspection was (Weld2-PRZ-22) end weld with U2C16 3/2006 U2C16 performed after the overlay was buttering applied.
Relief Nozzle to safe A PDI qualified inspection was end weld with U2C16 3/2006 U2C16 performed after the overlay was buttering applied.