L-2007-116, 10 CFR 50.46, Acceptance Criteria for Emergency Core Cooling Systems in Light Water Nuclear Power Reactors, 30-Day Special Report

10 CFR 50.46, Acceptance Criteria for Emergency Core Cooling Systems in Light Water Nuclear Power Reactors, 30-Day Special Report

ML072330126
Person / Time
Site:	Turkey Point
Issue date:	08/09/2007
From:	Jefferson W Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
James Connolly, 305-246-6632
References
L-2007-116
Download: ML072330126 (2)

Text

FPL August 9, 2007 L-2007-116 10 CFR 50.46 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555-00001 Re: Turkey Point Units 3 and 4 Docket Nos. 50-250 and 50-251 10 CFR 50.46, "Acceptance Criteria for Emergency Core Cooling Systems in Light Water Nuclear Power Reactors" Day Special Report By letter L-2007-092 dated June 25, 2007, Florida Power & Light (FPL) submitted a 30-day special report to notify the NRC of a change in Peak Clad Temperature (PCT) due to a computer code error in the design basis analysis of the Large Break Loss of Coolant Accident (LBLOCA).

The referenced letter reported a design basis LBLOCA PCT of 2104'F for Turkey Point Units 3 and 4 as a result of a PCT change of 40°F due to the computer code error and a respective cumulative change in PCT of 153°F.

In order to gain additional margin to the 10 CFR 50.46 criteria, FPL performed a reanalysis of the LBLOCA PCT using version 4.0 of the PAD fuel performance computer code instead of version 3.4 of the PAD fuel performance code previously used in the LBLOCA PCT analysis. By letter NF-FP-07-153 dated July 12, 2007, Westinghouse provided FPL the reanalysis results.

With this new assessment, a change of -1 18'F in LBLOCA PCT is calculated with a resultant cumulative change of 271'F in LBLOCA PCT. As a result, the Turkey Point Units 3 and 4 design basis LBLOCA PCT is changed from 2104'F to 1986°F. This is still well below the 10 CFR 50.46 limit of 2200°F.

10 CFR 50.46(a)(3)(ii) requires that licensees report within 30 days to the Commission significant changes to, or errors discovered in, the Emergency Core Cooling System (ECCS) evaluation models, or in the application of such models that affect the peak clad temperature calculation and their effect on the limiting ECCS analysis. 10 CFR 50.46 (a)(3)(i) defines a significant change or error as one which results in a calculated peak fuel cladding temperature different by more than 50'F from the temperature calculated for the limiting transient using the last acceptable model, or is a cumulation of changes and errors such that the sum of the absolute magnitudes of the respective temperature changes is greater than 50°F.

The change to the Turkey Point Units 3 and 4 LBLOCA Evaluation Model PCT is -1 180 F and the resultant absolute value of the cumulative changes is 271'F. In accordance with 10 CFR 50.46 this issue is reportable to the NRC within 30 days. This letter meets the 30-day reporting requirement. In addition to reporting, 10 CFR 50.46 also requires that a schedule be proposed for reanalysis or for taking other actions as may be needed to show compliance with the requirements of the regulation. As discussed above, Westinghouse has determined that the Turkey Point Units 3 and 4 LBLOCA design basis analysis maintains compliance with 10 CFR 50.46 requirements. Accordingly, no schedule for reanalysis is required,.....

an FPL Group company

L-2007-116 Page 2 of 2 Should there be any questions, please contact James Connolly, Licensing Manager, at 305-246-6632.

Vice President Turkey Point Nuclear Plant Attachment cc: Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, Turkey Point Plant