RS-11-172, Introduction of Lead Test Assemblies

Introduction of Lead Test Assemblies

ML113000036
Person / Time
Site:	Dresden
Issue date:	10/26/2011
From:	Gullott D Exelon Generation Co, Exelon Nuclear, Exelon Corp
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-11-172
Download: ML113000036 (2)

Text

Exelon Generation Company, LLC www,exeloncorp.com 4300 Winfield Road Nuclear Warrenville, IL 60555 RS-11-172 October 26, 2011 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-001 Dresden Nuclear Power Station, Unit 2 Renewed Facility Operating License No. DPR-19 NRC Docket No. 50-237

Subject:

Introduction of Lead Test Assemblies

References:

1. Topical Report CENPD-287-P-A, Fuel Assembly Mechanical Design Methodology for Boiling Water Reactors

2. Topical Report WCAP-15942-P-A, Fuel Assembly Mechanical Design Methodology for Boiling Water Reactors Supplement 1 to CENP-287

3. Topical Report WCAP-15942-P-A Supplement 1, Revision 0, Material Changes for SVEA-96 Optimal Fuel Assemblies The purpose of this letter is to notify the U.S. Nuclear Regulatory Commission of the use of Lead Test Assemblies (LTA) as stated in Reference 1. Westinghouse Electric Company LLC (Westinghouse) and Exelon Generation Company, LLC, have collaborated to introduce an advanced alloy channel material in the Dresden Nuclear Power Station, Unit 2. The advanced alloy material is a zirconium-based alloy, Low Tin ZIRLOTM. Low Tin ZIRLOTM as a channel material is not specifically identified in the Westinghouse licensing topical report (Reference 2). Therefore, the use of these channels requires the application of the LTA provision of Reference 1 requiring the NRC to be notified on the first application of new fuel designs prior to loading into a reactor.

In accordance with Reference 1, the elements of an approved licensing process for LTA programs include the following:

• All new designs and design features will be evaluated with the methodology accepted by the NRC relative to the approved design bases;

• Significant new design features will be tested prior to full reload application;

• The NRC will be notified of the first application of new fuel designs prior to loading into a reactor. New fuel designs and design features will be provided to the NRC for information as supplements to this topical report; and

October 26, 2011 U. S. Nuclear Regulatory Commission Page 2 Sufficient, post-irradiation surveillance program will be performed to confirm that the fuel, including fuel assemblies with new design features, are operating as expected.

Evaluation of the Low Tin ZIRLOTM channels was completed using the methodology accepted by the NRC, and the channels were demonstrated to meet the acceptance criteria for use. The use of the ZIRLOTM channel in place of the currently licensed Zircaloy-2 channel material will be limited to eight fuel assemblies. The features of the channel design were provided to the NRC in September 2010 in Reference 3 (ADAMS Accession No. ML102590064). Westinghouse plans a surveillance program on the LTAs to confirm that the fuel is operating as expected.

There are no regulatory commitments contained in this letter.

Should you have any questions concerning this letter, please contact Mr. Joseph Bauer at (630) 657-2804.

Respectfully, David M. Gullott Manager - Licensing Exelon Generation Company, LLC cc: NRC Regional Administrator, Region Ili NRC Senior Resident Inspector - Dresden Nuclear Power Station NRR Project Manager - Dresden Nuclear Power Station