ML113360338

Closeout of Commitment Associated with Relief Request RR-1 0-02 Concerning the Weld Overlay of Pressurizer Spray Nozzle to Safe-End and Safe-End to Elbow Dissimilar Metal Welds and Completion of Inspection.

ML113360338
Person / Time
Site:	Three Mile Island
Issue date:	12/02/2011
From:	Jesse M D Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
TMI-11-166, RR-10-02, NRR-07-029
Download: ML113360338 (3)

Text

10 CFR 50.55a TMI-11-166 December 2, 2011 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 Commitment Associated with Relief Request RR-1 0-02 Concerning the Weld Overlay of the Pressurizer Spray Nozzle to Safe-End and Safe-End to Elbow Dissimilar Metal Welds and Completion of Inspection Commitments Associated with the Confirmatory Action Letter NRR-07-029

References:

1)Letter from P.B.Cowan (Exelon Generation Company, LLC)to U.S.Nuclear Regulatory Commission,"Submittal of Relief Request RR-10-02 Concerning the Weld Overlay of the Pressurizer Spray Nozzle to Safe-End and Safe-End to Elbow Dissimilar Metal Welds," dated September 30,2010 2)Letter from P.Bamford (U.S.Nuclear Regulatory Commission) to M.J.Pacilio,"Three Mile Island Nuclear Station, Unit 1-Request for Additional Information Regarding Relief Request RR-10-02, Weld Overlay of the Pressurizer Spray Nozzle to Safe-End and Safe-End to Elbow Dissimilar Metal Welds (TAC NO.ME4795)," dated February 28,2011 3)Letter from D.P.Helker (Exelon Generation Company, LLC)to U.S.Nuclear Regulatory Commission,"Response to Request for Additional InformationSubmittal of Relief Request RR-10-02 Concerning the Weld Overlay of the Pressurizer Spray Nozzle to Safe-End and Safe-End to Elbow Dissimilar Metal Welds," dated March 9, 2011 4)Letter from D.P.Helker (Exelon Generation Company, LLC)to U.S.Nuclear Regulatory Commission,"Response to Request for Additional InformationSubmittal of Relief Request RR-10-02 Concerning the Weld Overlay of the Pressurizer Spray Nozzle to Safe-End and Safe-End to Elbow Dissimilar Metal Welds," dated April 6, 2011 Closeout of Commitments*

Relief Request RR-10-02 and Confirmatory Action Letter NRR-07-029 December 2, 2011 Page 2 5)Letter from D.P.Helker (Exelon Generation Company, LLC)to U.S.Nuclear Regulatory Commission,"Response to Request for Additional InformationSubmittal of Relief Request RR-10-02 Concerning the Weld Overlay of the Pressurizer Spray Nozzle to Safe-End and Safe-End to Elbow Dissimilar Metal Welds," dated April 25, 2011 6)Letter from H.K.Chernoff (U.S.Nuclear Regulatory Commission) to M.J.Pacilio (Exelon Generation Company, LLC),"Three Mile Island Nuclear Station, Unit 1-Proposed Alternative RR-10-02 Regarding Weld Overlay of the Pressurizer Spray Nozzle to Safe-End and Safe-End to Elbow Dissimilar Metal Welds (TAC NO.ME4795)," dated August 15, 2011 7)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, Exelon Generation Company, LLC (Exelon)requested relief to perform a weld overlay of pressurizer spray nozzle to safe-end and safe-end to elbow dissimilar metal welds at Three Mile Island Nuclear Station (TMI), Unit 1.In the Reference 6 letter, the U.S.Nuclear RegulatoryCommissionapproved 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 pressurizer spray nozzle welds PR-009BM and SP-021 BM within 30 days after the completion of the last ultrasonic examination of the weld overlays during the fall 2011 TMI, Unit 1refuelingoutage.

The results would include a list of the indications detected, the disposition of all the indications using the standards of ASME Section XI, Nonmandatory Appendix 0, and the type and, if possible, the nature of the indications.

During the recent TMI, Unit 1refuelingoutage, the identified welds were successfully overlaid.Ultrasonic examinations of these overlays did not identify any indications.

It is noted that during initial ultrasonic examination and dimensional verification of the weld overlay, it was discovered that the weld overlay was approximately

0.3 inches

too short on the elbow side of the overlay.Additional weld material was added to the length of the overlay to bring the length within original design requirements and allow 100%coverage of the required ultrasonic examination volume.Accordingly, this commitment is complete.It is also noted that in Reference 7, the U.S.Nuclear Regulatory Commission acknowledged completion of the commitments associated with the mitigation of the Alloy 600/82/182 pressurizer butt welds with the exception of the commitment to re-examine with ultrasonic techniques the unmitigated welds identified in Confirmatory Action Letter NRR-07-029.

As stated in Reference 7, Confirmatory Action Letter NRR-07-029 would remain open until all commitments are completed.

With the weld overlay of the pressurizer spray nozzle welds PR-009BM and SP-021 BM, the Alloy 600/82/182 pressurizer butt welds identified in Confirmatory Action Letter NRR-07-029 have been mitigated.

Accordingly, the commitment to re-examine with ultrasonic techniques the unmitigated welds identified in the Confirmatory Action Letter NRR-07-029 is complete.

Closeout of Commitments

-Relief Request RR-10-02 and Confirmatory Action Letter NRR-07-029 December 2, 2011 Page 3 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, Michael D.Jesse Director-Licensing&Regulatory Affairs Exelon Generation Company, LLC cc: Regional Administrator, Region I, USNRC USNRC Senior Resident Inspector, TMI USNRC Project Manager,[TMI]USNRC