RS-06-043, Additional Information Supporting Request for License Amendment Regarding Transition to Westinghouse Fuel

Additional Information Supporting Request for License Amendment Regarding Transition to Westinghouse Fuel

ML060820353
Person / Time
Site:	Dresden, Quad Cities
Issue date:	03/23/2006
From:	Simpson P Exelon Generation Co, Exelon Nuclear
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RS-06-043
Download: ML060820353 (2)

Text

555 March 23, 2006 U . S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Dresden Nuclear Power Station, Units 2 and 3 Renewed Facility Operating License Nos. DPR-19 and DPR-25 NRC Docket Nos. 50-237 and 50-249 Quad Cities Nuclear Power Station, Units 1 and 2 Renewed Facility Operating License Nos. DPR-29 and DPR-30 NRC Docket Nos. 50-254 and 50-265 Subject : Additional Information Supporting Request for License Amendment Regarding Transition to Westinghouse Fuel

References:

1. Letter from P. R. Simpson (Exelon Generation Company, LLC) to U.S. NRC, "Request for License Amendment Regarding Transition to Westinghouse Fuel," dated June 15, 2005

2. Letter from P. R. Simpson (Exelon Generation Company, LLC) to U . S. NRC, "Additional Information Supporting Request for License Amendment Regarding Transition to Westinghouse Fuel," dated February 22, 2006 In Reference 1, Exelon Generation Company, LLC (EGC) requested an amendment to Renewed Facility Operating License Nos . DPR-19 and DPR-25 for Dresden Nuclear Power Station (DNPS) Units 2 and 3, and Renewed Facility Operating License Nos. DPR-29 and DPR-30 for Quad Cities Nuclear Power Station (QCNPS) Units 1 and 2. The proposed amendment supports the transition to Westinghouse SVEA-96 Optimal fuel at DNPS and QCNPS .

EGC provided additional information to support NRC review of the proposed amendment in Reference 2 . Attachment 1 of Reference 2 documented results of the reanalysis that was performed to justify the acceptability of the application of the Westinghouse Emergency Core Cooling System evaluation methodology for the transition to SVEA-96 Optimal fuel.

March 23, 2006 U . S . Nuclear Regulatory Commission Page 2 An error was identified recently that affects some of the information that was submitted to the NRC in Attachment 1 of Reference 2. Specifically, the results related to the automatic depressurization system (ADS) failure case presented in Figure 4-3 and Section 4.2.5, "Case 5:

ADS Failure," are incorrect. The error affects only the small break loss-of-coolant accident cases with ADS failure (i.e., not the limiting loss-of-coolant accident case) . The large break loss-of-coolant accident calculations are unaffected . Therefore, relative to 10 CFR 50.46, the assessment of the impact to PCT is OOF. Additionally, the conclusions of the break spectrum analysis are unaffected .

The error was the result of an input discrepancy where the ADS capacity was not reduced as it was intended for the ADS failure cases presented in Attachment 1 of Reference 2. Correction of the error reduces the ADS capacity for these runs, which affects the PCT results for the ADS failure cases. A compensating correction has also been identified and applied as part of the correction of the error. Specifically, in the model, the ADS timer was erroneously reset, delaying the actuation . Preliminary evaluations by Westinghouse indicated that the combined effect of the corrections is an overall improvement (i.e., reduction) in thethePCT results for the ADS failure cases. Therefore, the conclusions of the break spectrum and calculated results for the 10 CFR 50.46 criteria (i.e ., PCT, local oxidation, core-wide oxidation, coolable geometry, and the provisions for long-term cooling) are unaffected .

significant EGC has reviewed the information supporting a finding of no hazards consideration that was previously provided to the NRC in Reference 1 . The information provided in this submittal does not affect the bases for concluding that the proposed license amendment does not involve a significant hazards consideration.

There are no regulatory commitments contained in this letter . Should you have any questions related to this letter, please contact Mr. Kenneth M . Nicely at (630) 657-2803 .

I declare under penalty of perjury that the foregoing is true and correct . Executed on the 23rd day of March 2006.

Respectfully, Patrick R. Simpson Manager - Licensing