BYRON 2004-0038, Steam Generator Tube Repairs Resulting from Byron, Unit 2, Cycle 11 Refueling Outage

Steam Generator Tube Repairs Resulting from Byron, Unit 2, Cycle 11 Refueling Outage

ML041170314
Person / Time
Site:	Byron
Issue date:	04/17/2004
From:	Kuczynski S Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
3.11.0530, BYRON 2004-0038
Download: ML041170314 (2)

Text

ExekInSm Exelon Generation Company. LLC www.exeloncorp.com Nuclear Byron Station 4450 North German Church Road Byron, IL 61010-9794 April 17, 2004 LTR: BYRON 2004-0038 File: 3.11.0530 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Unit 2 Facility Operating License No. NPF-66 NRC Docket No. STN 50-455

Subject:

Steam Generator Tube Repairs Resulting from Byron Station, Unit-2, Cycle 11 Refueling Outage Pursuant to Item a of Technical Specification 5.6.9, "Steam Generator (SG) Tube Inspection Reports," we are reporting the number of SG tubes plugged or repaired during Byron Station, Unit-2, Cycle 11 Refueling Outage.

A 100% full-length eddy current bobbin coil inspection and 25% plus-point inspection of the hot leg top of tubesheet and low row U-bend regions were performed on all four Unit-2 steam generators. Twenty-five percent of the total population of hot leg dents and dings that had bobbin coil voltage amplitudes greater than 5 volts were also inspected with a rotating probe (plus-point) in all steam generators. In addition, a 25% plus-point point inspection of the pre-heater baffle plate expansions was performed in two steam generators.

Based upon the results of this inspection, steam generator 2A was classified as inspection category C-2. A total of 92 tubes were plugged during the current Byron Station, Unit-2, Cycle 11 Refueling Outage. All of the tubes plugged were in the 2A steam generator. Out of the 92 tubes plugged in the 2A steam generator, 90 of the tubes were preventatively plugged based on the 2A steam generator waterbox inspection results. The remaining two tubes plugged in the 2A steam generator were required to be plugged due to exceeding the Technical Specification repair limit.

No tubes were plugged in the 2B, 2C, and 2D steam generators. Based upon the results of this inspection, steam generators 2B, 2C, and 2D were classified as inspection category C-1 in accordance with Technical Specification 5.5.9.c, "Inspection Results Classification."

The plugging distribution between the SGs is summarized in the table below.

W-Byron Ltr. 2004-0038 April 17, 2004 Page 2 Steam Tubes Plugged Tubes Total Tubes

. Generator this Outage Plugged Plugged*

(B2R11) Previously 2A 92 52 144 2B 0 113 113 2C 0 53 53 2D 0 22 22 Total 92 240 332

• Each SG contains 4570 tubes If there are any questions regarding this information, please contact Mr. W. Grundmann, Regulatory Assurance Manager, at (815) 406-2800.

Respectfully,

• &A 2czrv Stephen E. Kuczynski Site Vice President Byron Nuclear Generating Station SEK/JS/DD/rah cc: Regional Administrator - NRC Region IlIl NRC Senior Resident Inspector - Byron Station