TMI-10-014, Inspection Results of Alloy 600/82/182 Pressurizer Butt Welds

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Inspection Results of Alloy 600/82/182 Pressurizer Butt Welds
ML100330134
Person / Time
Site: Three Mile Island Constellation icon.png
Issue date: 02/01/2010
From: Cowan P
Exelon Generation Co, Exelon Nuclear
To:
Document Control Desk, Office of Nuclear Reactor Regulation
References
TAC MD4191, TMI-10-014
Download: ML100330134 (2)


Text

Exelon Nuclear 200 Way Kennett Square, PA 19348 TMI-1O-014 February 1, 2010 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Three Mile Island, Unit 1 Facility Operating License No. DPR-50 NRC Docket No. 50-289

Subject:

Inspection Results of Alloy 600/82/182 Pressurizer Butt Welds

References:

(1) Letter from T. S. O'Neill (AmerGen Energy Company, LLC) to U.S.

Nuclear Regulatory Commission, "Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt Welds," dated January 30,2007 (2) Letter from T. S. O'Neill (AmerGen Energy Company, LLC) to U.S.

Nuclear Regulatory Commission, "Supplemental Response Regarding Inspection and Mitigation of Alloy 600/82/182 Pressurizer Butt Welds,"

dated February 21,2007 (3) Letter from J. E. Dyer (U.S. Nuclear Regulatory Commission) to C. M. Crane (AmerGen Energy Company, LLC), "Confirmatory Action Letter, Three Mile Island Nuclear Station, Unit NO.1 (TAC NO. MD4191 ),"

dated March 22, 2007 (4) Letter from R. G. West (AmerGen Energy Company, LLC) to U.S. Nuclear Regulatory Commission, "Pressurizer Weld Overlay Examination Results and Closeout of Confirmatory Action Letter Requirements (TAC NO.

MD4191 )," dated December 4, 2007 (5) Letter from C. Haney (U.S. Nuclear Regulatory Commission) to C. G.

Pardee (AmerGen Energy Company, LLC), "Three Mile Island Nuclear Station, Unit 1 - Acknowledgement of Actions Taken For Confirmatory Action Letter NRR-07-029 (TAC NO. MD4191)," dated January 29,2008 In the Reference 1 letter, AmerGen Energy Company, LLC (now Exelon Generation Company, LLC) provided a supplemental response regarding inspection and mitigation of Alloy 600/82/182 pressurizer butt welds. In the Reference 2 letter, Three Mile Island Nuclear Station (TMI), Unit 1 committed to reporting Alloy 600/82/182 pressurizer nozzle connection inspection results for all inspections performed after February 28,2007 until the nozzles are mitigated. The particular nozzles were identified in Attachment 1 to the Reference 2 letter.

Since that time, the three (3) 2Y2-inch pressure relief nozzles and the 10-inch surge nozzle have been mitigated.

Results of Alloy 600/82/182 Pressurizer Butt Welds February 1, 2010 Page 2 During the recent TMI, Unit 1 outage (T1 R18), the 4-inch pressurizer spray nozzle was bare metal visual inspected in accordance with 10CFR50.55a(g)(6)(ii)(E) and remains unmitigated. The inspection did not identify any reportable indications. This nozzle is scheduled for volumetric inspection or mitigation during the 2011 refueling outage.

This submittal does not contain any new regulatory commitments.

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

Respectfully, Pamela Cowan Director - Licensing and Regulatory Affairs Exelon Generation Company, LLC cc: S. J. Collins, Regional Administrator, Region I, USNRC D. M. Kern, USNRC Senior Resident Inspector, TMI P. Bamford, Project Manager, USNRC