RS-15-059, Units 1 & 2 - Update to LRA Section 4.3.4, Class 1 Component Fatigue Analyses Supporting GSI-190 Closure, Related to License Renewal Application

Units 1 & 2 - Update to LRA Section 4.3.4, Class 1 Component Fatigue Analyses Supporting GSI-190 Closure, Related to License Renewal Application

ML15040A179
Person / Time
Site:	Byron, Braidwood
Issue date:	02/06/2015
From:	Gallagher M Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-15-059
Download: ML15040A179 (4)

Text

Michael P. Gallagher Vice President. License Renewal Exelon Generation Exelon Nuclear 200 Exelon Way Kennett Square. PA 19348 610 765 5958 Office 610 765 5956 Fax www.exeloncorp.com michaelp.gallagher@exeloncorp.com 10 CFR 50 10 CFR 51 10 CFR 54 RS-15-059 February 6, 2015 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, DC 20555-0001 Braidwood Station, Units 1 and 2 Facility Operating License Nos. NPF-72 and NPF-77 NRC Docket Nos. STN 50-456 and STN 50-457 Byron Station, Units 1 and 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455

Subject:

Update to LRA Section 4.3.4, "Class 1 Component Fatigue Analyses Supporting GSl-190 Closure," related to the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application

References:

1. Letter from Michael P. Gallagher, Exelon Generation Company LLC (Exelon) to NRC Document Control Desk, dated May 29, 2013, "Application for Renewed Operating Licenses"

2. Letter from Michael P. Gallagher, Exelon Generation Company LLC (Exelon) to NRC Document Control Desk, dated November 25, 2014, "Response to NRC Request for Additional Information, Set 43, dated October 28, 2014, related to the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2, License Renewal Application" In Reference 1, Exelon Generation Company, LLC (Exelon) submitted the License Renewal Application (LRA) for the Byron Station, Units 1 and 2, and Braidwood Station, Units 1 and 2 (BBS). In Reference 2, Exelon responded to NRC RAI 4.3.4-3b, in part, providing justification for the leading component material locations bounding other component material locations in a transient section when using screening methodology to determine the leading locations for the consideration of environmentally assisted fatigue (EAF).

Exelon and the NRC staff held a discussion on January 27, 2015 regarding a draft follow-up RAI (4.3.4-3c), which the staff was considering issuing to Exelon in order to acquire more detailed justification for screening out the Lower Head at Heater Penetration (Pressurizer Transient

February 6, 2014 U.S. Nuclear Regulatory Commission Page 2 of 2 Section), the Upper Shell (Pressurizer Transient Section), and the Inlet & Outlet Nozzle, Weld (Unit 1 RSG Transient Section) locations when compared to the leading location in the transient section. Exelon proposed an alternative method of resolving the staff's concern by submitting an amendment to the LRA which would screen in the above locations, and add them to locations already determined to bound other locations. The Enclosure to this letter contains the changes to the LRA as a result of screening in these three locations by adding them to the list of leading equipment locations contained in LRA Table 4.3.4-2 on page 4.3-33. As stated in the disposition of the TLAA in Section 4.3.4 of the LRA, these locations will be monitored by the Fatigue Monitoring Program and action will be required prior to exceeding an environmental fatigue usage factor limit of 1.0.

There are no new or revised regulatory commitments contained in this letter.

If you have any questions, please contact Mr. Al Fulvio, Manager, Exelon License Renewal, at 610-765-5936.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on ~i.,, I J ,. , J ()I.S-Respectfully, M~ ~--

Vice President - License Renewal Projects Exelon Generation Company, LLC

Enclosure:

Byron and Braidwood Stations, Units 1 and 2, Update to License Renewal Application Section 4.3.4 cc: Regional Administrator - NRC Region Ill NRC Project Manager (Safety Review), NRR-DLR NRC Project Manager (Environmental Review), NRR-DLR NRC Senior Resident Inspector, Braidwood Station NRC Senior Resident Inspector, Byron Station NRC Project Manager, NRR-DORL-Braidwood and Byron Stations Illinois Emergency Management Agency - Division of Nuclear Safety

RS-15-059 Enclosure Page 1 of 2 Enclosure Byron and Braidwood Stations, Units 1 and 2, Update to License Renewal Application Section 4.3.4 Note: To facilitate understanding, portions of the LRA have been repeated in this Enclosure, with revisions indicated. Original LRA text is shown in normal font. Additions to the LRA due to this submittal are highlighted with bolded italics.

RS-15-059 Enclosure Page 2 of 2 LRA Section 4.3.4, Table 4.3.4-2 shown on page 4.3-33 of the LRA, is revised to add three leading locations as shown below. The added locations and the corresponding additional information are shown in bolded italics.

Table 4.3.4-2 Byron and Braidwood Stations, Units 1 and 2: EAF Screening Leading Locations - Equipment CUF Screening Equipment Component Material (2) CUFen Reactor Vessel Outlet Nozzle (safe end) SS 0.11 1.688 Pressurizer Surge Nozzle(1) SS 0.9336 14.33 Pressurizer Lower Head at Heater Penetration LAS 0.8586 2.108 Upper Shell LAS 0.992 2.435 OSG - Primary Manway Drain Hole CS 0.99 1.72 OSG - Primary Chamber Drain NI 0.594 2.687 Steam Generator RSG - Primary Head/Tubesheet LAS 0.88 2.16 Juncture RSG - Inlet and Outlet Nozzle, NI 0.12 1.842 (3)

Weld Casing Suction Nozzle SS 0.581 8.92 Reactor Coolant Pump Thermal Barrier SS 0.4463 6.85 Notes:

(1) NUREG/CR-6260 location (2) The CUFs shown in this table are from the fatigue analyses of record for each respective component. The NUREG/CR-6260 location was re-evaluated for fatigue with environmental effects included. The new results are shown in Table 4.3.4-1.

(3) Screening CUFen was computed conservatively using the SS maximum Fen of 15.348.

CS - Carbon Steel LAS - Low Alloy Steel SS - Stainless Steel NI - Nickel Alloy OSG - Unit 2 Original Steam Generator RSG - Unit 1 Replacement Steam Generator