L-2014-037, Emergency Core Cooling Systems in Light Water Nuclear Power Reactors - 30 Day Special Report

Emergency Core Cooling Systems in Light Water Nuclear Power Reactors - 30 Day Special Report

ML14069A082
Person / Time
Site:	Turkey Point
Issue date:	02/18/2014
From:	Kiley M Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2014-037
Download: ML14069A082 (2)

Text

SFebruary 18, 2014 L-20.14-037 FPL. 10 CFR 50.46 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, D. C. 20555-0001 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" - 30 Day Special Report

References:

1. FPL letter, M. Kiley to U. S. Nuclear Regulatory Commission, "Turkey Point Units 3 and 4, Dockets Nos. 50-250 and 50-251, 10 CFR 50.46, 'Acceptance Criteria for Emergency Core Cooling Systems in Light Water Nuclear Power Reactors' - 30 Day Special Report," L-2013-237, August 20, 2013.

2. Westinghouse letter, E. Malek to R. Klein, "Turkey Point Unit 3 & 4, 10 CFR 50.46 Report for the HOTSPOT Burst Strain Error Correction," NF-FP-14-9, January 31, 2014.

10 CFR 50.46(a)(3)(ii) requires that changes to the Large Break Loss of Coolant Accident (LBLOCA) Evaluation Model (EM) and Small Break LOCA (SBLOCA) EM peak clad temperature (PCT) exceeding 50°F have to be reported to the NRC within 30 days. This letter meets this requirement.

FPL letter L-2013-237 (Reference 1), submitted the Turkey Point Units 3 and 4 30-day special report documenting several errors in the Turkey Point LBLOCA EM. The LBLOCA PCT reported was 2115 OF with a cumulative change of 71 OF.

Westinghouse identified an error in the LBLOCA EM in the calculation of the burst strain performed by the HOTSPOT code (Reference 2). Correction of the error yields a thinner cladding at the burst node and consequently more fuel relocating into the burst node leading to an increase in PCT at the burst node. The impact of this error was evaluated with the most limiting Turkey Point HOTSPOT runs with a HOTSPOT version that included the correction of the error and resulted in an estimated PCT impact of +18 OF. Table 1 below provides a summary of the new LBLOCA PCT for Turkey Point Units 3 and 4. The revised LBLOCA PCT for Units 3 and 4 is 2133 OF with a cumulative change of 89°F due to the EM error. The SBLOCA EM is not affected by the identified error.

Florida Power & Light Company 9760 SW 344 St Homestead, FL 33035

a L-2014-037 Page 2 of 2 Table 1 Turkey Point Units 3 and 4 LBLOCA Evaluation Model Error Peak Cladding Cumulative Temperature Change LBLOCA 10 CFR 50.46 30-day Special Report (Ref.1) 2115 OF 71 OF ECCS Model Assessments (Ref. 2) 18 OF 18 OF 2133 OF 89 OF 10 CFR 50.46(a)(3)(ii) also requires that a schedule for reanalysis be provided or compliance with the requirements of the regulation be shown if the error is significant. For the Turkey Point Units continued compliance with 10 CFR 50.46 requirements is demonstrated by the new estimated LBLOCA PCT of 2133°F remaining below the limit of 22000 F.

Should there be any questions, please contact Robert Tomonto, Licensing Manager, at 305-246-7327.

Very truly yours, Michael Kiley Vice President Turkey Point Nuclear Plant cc: Regional Administrator, Region II, USNRC Senior Resident Inspector, USNRC, Turkey Point Plant