BYRON 2008-0054, Response to NRC Request Concerning Unresolved Item 05000454/2008008 and 05000455/2008008

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

ML081560649
Person / Time
Site:	Byron
Issue date:	06/04/2008
From:	Hoots D Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
BYRON 2008-0054, IR-08-008
Download: ML081560649 (2)

Text

Nuclear June 4,2008 LTR: BYRON 2008-0054 File: 2.01.0700 United States Nuclear Regulatory Commission Attention: 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:

Response to NRC Request Concerning Unresolved Item 0500045412008008 and0500045512008008

Reference:

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 ltem (URI) 0500045412008008; 05000455/2008008," dated May 5,2008 In the referenced letter, the NRC requested a response within 30 days with our proposed actions and schedule to resolve the noncompliance of the single failure assumptions used in our Ultimate Heat Sink (UHS) design basis analysis.

To achieve compliance, a design basis re-analysis of the UHS is being performed to evaluate the impact of postulated passive electrical single failures. The results of this analysis will be incorporated into the Byron Station design basis via requirements of 10 CFR 50.59, "Changes, tests, and experiments.'This is expected to be completed by December 5, 2008. We do not anticipate any physical modifications to the UHS will be necessary.

In the interim, we have invoked the provisions of Administrative Letter 98-10,

"'Dispostioningof Technical Specifications That are insufficient to Assure Plant Safety.'"

We have concluded that the UHS remains operable with administrative controls in place to ensure seven of the eight UHS cooling cells are operable to be within the Limiting Condition for Operations for Technical Specifications 3.8.9, "Ultimate Heat Sink.'"

These interim controls will remain in place until the design basis for the UHS is revised.

June 4,2008 U.S. Nuclear Regulatory Commission Page 2 There are no regulatory commitments associated with this response. Should you have any questions about this letter, please contact Mr. William Grundmann at (815) 406-2800.

Respectfully, David M. Hoots Site Vice President Byron Station cc: Regional Administrator - NRC Region Ill NRC Senior Resident Inspector - Byron Station Director, Office of Enforcement