TMI-13-168, Closeout of Commitments Associated with Relief Request RR-12-02 Concerning the Installation of a Full Structural Weld Overlay on the Lower Cold Leg Letdown Nozzle Dissimilar Metal Welds and Alloy 600 Safe-End

Closeout of Commitments Associated with Relief Request RR-12-02 Concerning the Installation of a Full Structural Weld Overlay on the Lower Cold Leg Letdown Nozzle Dissimilar Metal Welds and Alloy 600 Safe-End

ML13338A431
Person / Time
Site:	Three Mile Island
Issue date:	12/03/2013
From:	Jim Barstow Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TMI-13-168
Download: ML13338A431 (2)

Text

10 CFR 50.55a TMI-13-168 December 3, 2013 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555-0001 Three Mile Island Nuclear Station, Unit 1 Renewed Facility Operating License No. DPR-50 NRC Docket No. 50-289

Subject:

Closeout of Commitments Associated with Relief Request RR-12-02 Concerning the Installation of a Full Structural Weld Overlay on the Lower Cold Leg Letdown Nozzle Dissimilar Metal Welds and Alloy 600 Safe-End

References:

1) Letter from M. Jesse (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Submittal of Relief Request RR-12-02 Concerning the Installation of a Full Structural Weld Overlay on the Lower Cold Leg Letdown Nozzle Dissimilar Metal Welds and Alloy 600 Safe-End," dated October 18, 2012

2) Letter from P. Bamford (U.S. Nuclear Regulatory Commission) to M.

Pacilio (Exelon Generation Company, LLC), "Three Mile Island Nuclear Station, Unit 1 Request for Additional Information Regarding Relief Request RR-12-02, Relief Request Concerning Full Structural Weld Overlay of Dissimilar Metal Welds on the Lower Cold Leg Letdown Nozzle and Safe-End (TAC No. ME9818)," dated December 14, 2012

3) Letter from M. Jesse (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Response to Request for Additional Information

- Relief Request RR-12-02 Concerning the Installation of a Full Structural Weld Overlay on the Lower Cold Leg Letdown Nozzle Dissimilar Metal Welds and Alloy 600 Safe-End," dated January 17, 2013

4) Letter from D. Helker (Exelon Generation Company, LLC) to U.S. Nuclear Regulatory Commission, "Relief Request RR-12-02 Concerning the Installation of a Full Structural Weld Overlay on the Lower Cold Leg Letdown Nozzle Dissimilar Metal Welds and Alloy 600 Safe-End," dated March 11, 2013

5) Letter from V. Rodriguez (U.S. Nuclear Regulatory Commission) to M. J. Pacilio (Exelon Generation Company, LLC), "Three Mile Island Nuclear Station, Unit 1 - Proposed Alternative RR-12-02 Regarding Weld Overlay of the Lower Cold Leg Letdown Nozzle Dissimilar Metal Welds and Alloy 600 Safe-End (TAC NO. ME9818)," dated June 10,2013

Closeout of Commitments Associated with Relief Request RR-12-02 December 3, 2013 Page 2 In the Reference 1 letter, Exelon Generation Company, LLC (Exelon) requested relief to perform a weld overlay of the lower cold leg letdown nozzle to safe-end and safe-end to elbow dissimilar metal welds at Three Mile Island Nuclear Station (TMI), Unit 1. In the Reference 5 letter, the U.S. Nuclear Regulatory Commission approved this relief request.

As discussed in the Reference 1 submittal, Exelon committed to providing the results of the ultrasonic examination of the structural weld overlay on the TMI, Unit 1 lower cold leg letdown nozzle dissimilar metal welds and Alloy 600 safe-end within 30 days after the completion of the last ultrasonic examination of the weld overlays during the fall 2013 TMI, Unit 1 refueling outage. The results would include a list of the indications detected, the disposition of all the indications using the standards of ASME code Cases N-740-2 and N-770-1 and the type and, if possible, the nature of the indications. During the recent TMI, Unit 1 refueling outage, the identified welds were successfully overlaid. Ultrasonic examinations of these overlays did not identify any indications. Additionally, there were no repairs to the overlay material. Accordingly, this commitment is complete.

There are no regulatory commitments in this letter.

If you have any questions concerning this letter, please contact Tom Loomis at (610) 765-5510.

Respectfully, James Barstow Director - Licensing & Regulatory Affairs Exelon Generation Company, LLC cc: Regional Administrator, Region I, USNRC USNRC Senior Resident Inspector, TMI USNRC Project Manager, [TMI] USNRC