ML13050A636

Draft RAI Memo

ML13050A636
Person / Time
Site:	Three Mile Island
Issue date:	02/20/2013
From:	Peter Bamford Plant Licensing Branch 1
To:	Meena Khanna Plant Licensing Branch 1
Bamford P
References
TAC ME9788
Download: ML13050A636 (3)

Text

February 20, 2013 MEMORANDUM TO: Meena Khanna, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM: Peter Bamford, Project Manager /RA/

Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUBJECT:

THREE MILE ISLAND, UNIT NO. 1 - ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING END-OF-INTERVAL RELIEF REQUEST RR-12-01, PRESSURIZER NOZZLE-TO-HEAD WELD EXAMS (TAC NO. ME9788)

The attached draft request for additional information (RAI) was transmitted by electronic transmission on February 19, 2013, to Mr. Thomas Loomis, at Exelon Generation Company, LLC (Exelon, the licensee). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call (if needed) with Exelon in order to clarify the licensees end-of-interval relief request regarding the limited examination coverage of three pressurizer relief nozzle welds at Three Mile Island Nuclear Station, Unit 1. The draft RAI is related to the licensees submittal dated October 5, 2012. The draft question was sent to ensure that it was understandable, the regulatory basis was clear, and to determine if the information was previously docketed.

Additionally, review of the draft RAI would allow Exelon to evaluate and agree upon a schedule to respond to the RAI. This memorandum and the attachment do not represent an NRC staff position.

Docket No. 50-289

Enclosure:

As stated

February 20, 2013 MEMORANDUM TO: Meena Khanna, Chief Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation FROM: Peter Bamford, Project Manager /RA/

Plant Licensing Branch I-2 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation

SUBJECT:

THREE MILE ISLAND, UNIT NO. 1 - ELECTRONIC TRANSMISSION, DRAFT REQUEST FOR ADDITIONAL INFORMATION REGARDING END-OF-INTERVAL RELIEF REQUEST RR-12-01, PRESSURIZER NOZZLE-TO-HEAD WELD EXAMS (TAC NO. ME9788)

The attached draft request for additional information (RAI) was transmitted by electronic transmission on February 19, 2013, to Mr. Thomas Loomis, at Exelon Generation Company, LLC (Exelon, the licensee). This draft RAI was transmitted to facilitate the technical review being conducted by the Nuclear Regulatory Commission (NRC) staff and to support a conference call (if needed) with Exelon in order to clarify the licensees end-of-interval relief request regarding the limited examination coverage of three pressurizer relief nozzle welds at Three Mile Island Nuclear Station, Unit 1. The draft RAI is related to the licensees submittal dated October 5, 2012. The draft question was sent to ensure that it was understandable, the regulatory basis was clear, and to determine if the information was previously docketed.

Additionally, review of the draft RAI would allow Exelon to evaluate and agree upon a schedule to respond to the RAI. This memorandum and the attachment do not represent an NRC staff position.

Docket No. 50-289

Enclosure:

As stated DISTRIBUTION:

Public RidsNrrPMThreeMileIsland Resource LPL1-2 R/F Accession No.: ML13050A636* via email OFFICE LPL1-2/PM EVIB/BC NAME PBamford SRosenberg*

DATE 2/20/13 02/15/13 OFFICIAL RECORD COPY

REQUEST FOR ADDITIONAL INFORMATION THREE MILE ISLAND NUCLEAR STATION, UNIT 1 END-OF-INTERVAL RELIEF REQUEST RR-12-01 PRESSURIZER NOZZLE-TO-HEAD WELD EXAMS DOCKET NO. 50-289 By letter dated October 5, 2012 (Agencywide Documents Access and Management System Accession No. ML12283A252), Exelon Generation Company, LLC (Exelon, the licensee) submitted a relief request for U.S. Nuclear Regulatory Commission (NRC) approval. In the relief request, Exelon identifies the limited examination of three pressurizer relief nozzle welds at Three Mile Island Nuclear Station (TMI-1) for the third inservice inspection interval, which ended on April 19, 2012. According to the licensee, the coverage for each of the welds in question was approximately 40%, as compared to a specification of 90%, in accordance with American Society of Mechanical Engineers Code Case N-460, Alternative Examination Requirements for Class 1 and Class 2 Welds,Section XI, Division 1. The U.S. Nuclear Regulatory Commission (NRC) staff has been reviewing the submittal and has determined that additional information is needed to complete its review.

1.) The submittal does not include any statement regarding past inspection results, including preservice. The NRC staff is concerned that there could be a weld repair done during fabrication. If the repair used a Nickel-based alloy filler metal, the joint could be susceptible to primary water stress corrosion cracking.

Therefore, describe the results of all past inspections, including preservice, as well as any repairs that have been done to the subject pressurizer relief nozzle-to-vessel welds.

Enclosure