BYRON 2009-0025, Updated Information to Response to NRC Request Concerning Unresolved Item 05000454-08-008 and 05000455-08-008

Updated Information to Response to NRC Request Concerning Unresolved Item 05000454-08-008 and 05000455-08-008

ML090680514
Person / Time
Site:	Byron   (NPF-037, NPF-066)
Issue date:	03/05/2009
From:	Enright D Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
1.10.0101, 2.01.0700, BYRON 2009-0025
Download: ML090680514 (2)

Text

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BYRON 2009-0025 File:

2.01.0700 1.10.0101 United States Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Byron Station, Unit 1 and Unit 2 Facility Operating License Nos. NPF-37 and NPF-66 NRC Docket Nos. STN 50-454 and STN 50-455

Subject:

Updated Information to Response to NRC Request Concerning Unresolved Item 05000454/2008008 and 05000455/2008008

References:

(1)

Letter from Ann Marie Stone (USNRC) to Charles G. Pardee (Exelon Generation Company, LLC), "Byron Station, Units 1 and 2 Follow Up Inspection of an Unresolved Item (URI) 05000454/2008008; 05000455/2008008," dated May 5, 2008 (2)

Letter from David M. Hoots (Exelon Generating Company, LLC) to USNRC, "Response to NRC Request Concerning Unresolved Item 05000454/2008008; 05000455/2008008," dated June 4~2008 In Reference 1, the NRC requested a response describing our intended actions and proposed schedule to resolve the noncompliance of single failure assumptions used in our Ultimate Heat Sink (UHS) design basis analysis.

In Reference 2, Byron Station provided a response with intended actions and proposed schedule. The intended action was to perform a design basis re-analysis of the UHS to evaluate the impact of postulated passive electrical single failures. The results of this analysis would then be incorporated into the Byron Station design basis via requirements of 10 CFR 50.59, "Changes, tests, and experiments."

This was expected to be completed by December 5, 2008.

March 5, 2009 U.S. Nuclear Regulatory Commission Page 2 On November 3, 2008, it was determined that the 10 CFR 50.59 evaluation of the re-analysis results would likely conclude that a Technical Specification (TS) revision would be necessary. Consequently, a License Amendment Request (LAR) would need to be developed and submitted to receive NRC approval prior to revising the UHS design basis.

Due to delays in finalizing the re-analysis, the schedule is now targeted to support submittal of the LAR to the NRC by end of the second quarter 2009. Per NRC request, this letter is follow-up notification of the change of the LAR submittal date.

Resolution of this non-compliance will continue to be tracked via our corrective action program. Pending final resolution, we will also continue to comply with the provisions of Administrative Letter 98-10, "Dispositioning of Technical Specifications That are Insufficient to Assure Plant Safety," as described in Reference 2.

There are no regulatory commitments contained in this letter. Should you have any questions about this letter, please contact Mr. David Gudger at (815) 406-2800.

Respectfully,

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Site Vice President Byron Station DJE/JUcy cc:

Regional Administrator - NRC Region III NRC Senior Resident Inspector - Byron Station Director, Office of Enforcement