ML14307A117

Three Mile Island, Unit 1 - Request for Additional Information Regarding Relief Request RR-14-01 Concerning Alternative Root Mean Square Depth Sizing Requirements (TAC No. MF4873)

ML14307A117
Person / Time
Site:	Three Mile Island
Issue date:	11/14/2014
From:	Lamb J G Plant Licensing Branch 1
To:	Pacilio M J Exelon Nuclear
John Lamb, NRR/DORL 415-3100
References
TAC MF4873
Download: ML14307A117 (4)

Text

Mr. Michael J. Pacilio UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 November 14, 2014 President and Chief Nuclear Officer Exelon Nuclear 4300 Winfield Road Warrenville, IL 60555

SUBJECT:

THREE MILE ISLAND, UNIT 1 -REQUEST FOR ADDITIONAL INFORMATION REGARDING RELIEF REQUEST RR-14-01 CONCERNING ALTERNATIVE ROOT MEAN SQUARE DEPTH SIZING REQUIREMENTS (TAG NO. MF4873)

Dear Mr. Pacilio:

By letter dated September 19, 2014 (Agencywide Documents Access and Management System Accession No. ML 14262A002}, the Exelon Generation Company, LLC submitted Relief Request RR-14-01 requesting the use of alternate root mean square error criteria for sizing flaws that are greater than the requirements of American Society of Mechanical Engineers Code Case N-695, "Qualification Requirements for Dissimilar Metal Piping Welds," (N-695) at Three Mile Island Nuclear Station, Unit 1. The U.S. Nuclear Regulatory Commission (NRC) staff has reviewed the submittal, and has determined that a request for additional information (RAI) is needed to complete its technical review. The NRC staff's RAI is contained in the enclosure. A draft of these questions was previously sent to Mr. Dave Helker of your staff on November 3, 2014, with an opportunity to have a teleconference to ensure that the licensee understood the questions and their regulatory basis, as well as to verify that the information was not previously docketed. A conference call was held on November 10, 2014, and Mr. Thomas Loomis of your staff agreed that Exelon would respond to the RAI by December 5, 2014.

M. Pacilio If you have any questions regarding this letter, please feel free to contact me at (301) 415-3100 . Docket No. 50-289

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv . Lamb, Senior Project Manager Licensing Branch 1-2 Di ion of Operating Reactor Licensing Office of Nuclear Reactor Regulation REQUEST FOR ADDITIONAL INFORMATION RELIEF REQUEST RR-14-01 FOR THE FOURTH 10-YEAR INSPECTION INTERVAL EXELON GENERATION COMPANY, LLC THREE MILE ISLAND NUCLEAR STATION, UNIT 1 DOCKET NO. 50-289 (TAC NO. MF4873) By letter dated September 19, 2014 (Agencywide Document Access and Management System (ADAMS) Accession No. ML 14262A002), the Exelon Generation Company, LLC (the licensee) submitted Relief Request RR-14-01 requesting the use of alternate root mean square (RMS) error criteria for sizing flaws that are greater than the requirements of American Society of Mechanical Engineers (ASME) Code Case N-695, "Qualification Requirements for Dissimilar Metal Piping Welds," (N-695) at Three Mile Island Nuclear Station, Unit 1. The U.S. Nuclear Regulatory Commission staff requests that the licensee provide additional information to support RR-14-01 from the RMS depth sizing requirements of ASME Code and ASME Code Case N-695. 1. What are the thickness of Core Flood Nozzles A and B and their associated safe ends? 2. Please describe the inner diameter surface conditions of the weld on lays for the core flood nozzle-to-safe end welds (e.g., machined, ground smooth, as-welded, etc.). 3. Figure 1, "Core Flood "B" Nozzle to Safe-End Weld (RCT0001 RC0009BMWELD)," shows that the weld onlay is made of Alloy 82. Please confirm if the onlay is Alloy 82. Enclosure

• ML 14307 A 117 .. Sincerely, IRA! John G. Lamb, Senior Project Manager Plant Licensing Branch 1-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation *via memo **via e-mail OFFICE DORLILPL 1-2/PM DORL/LPL 1-2/PM DORLILPL 1-2/LA DE/EPNB/BC* DORLILPL 1-2/BC NAME Jlamb Tlamb A Baxter DAiley MKhanna DATE 11/10/14 11/04/14 11/13/14 10/30/14 11/14/14