SBK-L-14073, Best Estimate Large Break Loss of Coolant Accident 10 CFR 50.46 30-Day Report

Best Estimate Large Break Loss of Coolant Accident 10 CFR 50.46 30-Day Report

ML14111A402
Person / Time
Site:	Seabrook
Issue date:	04/16/2014
From:	Ossing M NextEra Energy Seabrook
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
SBK-L-14073
Download: ML14111A402 (4)

Text

NEXTera ENEROyp April 16, 2014 10 CFR 50.46 Docket No. 50-443 SBK-L-14073 United States Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001 Seabrook Station Best Estimate Large Break Loss of Coolant Accident 10 CFR 50.46 30-Day Report

Reference:

NextEra Energy Seabrook, LLC letter SBK-L-14040, "Best Estimate Large Break Loss of Coolant Accident (BE LBLOCA) 10 CFR 50.46 30-Day Report,"

February 18, 2014 In accordance with the requirements of 10 CFR 50.46(a)(3)(ii), NextEra Energy Seabrook, LLC (NextEra) submitted the referenced letter to report the impact of errors on the Seabrook Best Estimate Large Break Loss of Coolant Accident (BE LBLOCA). The reported BE LBLOCA peak clad temperature and cumulative change were 1939 OF and 155 OF, respectively.

10 CFR 50.46(a)(3)(ii) requires that changes to the BE LBLOCA Evaluation Model (EM) and small break LOCA EM resulting in cumulative changes and errors such that the sum of the absolute magnitudes of the respective temperature changes is greater than 50 OF be reported to the NRC within 30 days. This 30-day report documents changes and errors in the Seabrook BE LBLOCA analysis.

The enclosure provides the new BE LBLOCA PCT rackup for Seabrook Station that accounts for the changes and errors. The BE LBLOCA predicted values for the PCT and the cumulative change are 1939 °F and 155 OF, respectively. These values are unchanged from those provided in the referenced letter.

NextEra Energy Seabrook, LLC.

626 Lafayette Rd, Seabrook, NH 03874

U. S. Nuclear Regulatory Commission SBK-L-14073 / Page 2 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. Continued compliance with 10 CFR 50.46 requirements is demonstrated by the total estimated PCT value of 1939 OF remaining well below the limit of 2200 OF.

Should you have any questions regarding this report, please contact me at (603) 773-7512.

Sincerely, NextEra LLC Licensing Manager cc: NRC Region I Administrator J. Lamb, NRC Project Manager, Project Directorate 1-2 NRC Senior Resident Inspector

ENCLOSURE TO SBK-L-14073 Seabrook 10 CFR 50.46 30-Day Report for BE LBLOCA PCT Peak Clad Cumulative BE LBLOCA Temperature Change 2014 10 CFR 50.46 30-Day Report(') 1939 OF 155 OF Changes / Errors

- Grid Heat Transfer Enhancement (2) 0 OF 0 OF

- Changes to Grid Blockage Ratio and Porosity (2) 0 OF 0 OF 10 CFR 50.46 30-Day Report 1939 OF 155 OF References

1. NextEra Energy letter, M. H. Ossing to U.S. Nuclear Regulatory Commission, "Seabrook Station Best Estimate Large Break Loss of Coolant Accident (BE LBLOCA) 10 CFR 50.46 30-day Report" SBK-L-14040, February 18, 2014.

2. Westinghouse letter, E. M. Malek to J. Perryman, "NextEra Energy Seabrook Station 10 CFR 50.46 Annual Notification and Reporting for 2013," NF-NA 42, March 18, 2014.