ML15133A324

Turkey Point, Units 3 and 4 - 10 CFR 50.46, Acceptance Criteria for Emergency Core Cooling Systems in Light Water Nuclear Power Reactors - 2014 Annual Report

ML15133A324
Person / Time
Site:	Turkey Point
Issue date:	04/28/2015
From:	Kiley M Florida Power & Light Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-205-113
Download: ML15133A324 (4)

Text

April 28, 2015L-2015-113FPL. 10 CFR 50.46U.S. Nuclear Regulatory CommissionAttn: Document Control DeskWashington, D. C. 20555-0001Re: Turkey Point Units 3 and 4Docket Nos. 50-250 and 50-25110 CFR 50.46, "Acceptance Criteria forEmergency Core Cooling Systems in Light WaterNuclear Power Reactors" -2014 Annual Report

References:

1. FPL letter from Michael Kiley to U.S. NRC Document Control Desk, "Turkey Point Units 3and 4, Docket Nos. 50-250 and 50-251, 10 CFR 50.46, 'Acceptance Criteria for EmergencyCore Cooling Systems in Light Water Nuclear Power Reactors' -2013 Annual Report and30-Day Special Report," L-2014-084, April 6, 2014.2. 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 CoreCooling Systems in Light Water Nuclear Power Reactors' -30 Day Special Report," L-2014-037, Accession No. ML14069A082, February 18, 2014.3. FPL letter, M. Kiley to U. S. Nuclear Regulatory Commission, "Turkey Point Unit 3, DocketsNo. 50-250, 10 CFR 50.46, 'Acceptance Criteria for Emergency Core Cooling Systems inLight Water Nuclear Power Reactors'- 30 Day Special Report," L-2014-077, Accession No.ML14098A469, March 24, 2014.4. FPL letter, M. Kiley to U. S. Nuclear Regulatory Commission, "Turkey Point Units 4, DocketsNo. 50-251, 10 CFR 50.46, 'Acceptance Criteria for Emergency Core Cooling Systems inLight Water Nuclear Power Reactors' -30 Day Special Report," L-2014-302, Accession No.ML14310A292, October 15, 20145. 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 CoreCooling Systems in Light Water Nuclear Power Reactors'- 30 Day Special Report," L-2014-359, Accession No. ML14351A073, December 3, 2014.6. Westinghouse Letter, M. W. James to R. Klein, "Florida Power and Light Company TurkeyPoint Units 3 & 4- 10 CFR 50.46 Annual Notification and Reporting for 2014," NF-NEXT-1 5-46, March 9, 2015.10 CFR 50.46 2013 Annual Report10 CFR 50.46(a)(3)(ii) requires that licensees report to the Commission at least annually thenature of changes to, or errors discovered in, the Emergency Core Cooling System (ECCS)evaluation models (EM), or in the application of such models that affect the peak cladtemperature calculation and their effect on the limiting ECCS analysis. Table 1 provides theFlorida Power & Light Company (FPL) 10 CFR 50.46 Peak Cladding Temperature (PCT) 2014report for Turkey Point Units 3 and 4.Florida Power & Light Company ODD-9760 SW 344 St Homestead, FL 33035 P"(

L-2015-113Page 2 of 4FPL letter L-2014-084 (Reference 1), submitted the 2013 10 CFR 50.46 Annual Report and a30-Day Special Report. The 2013 annual report documented the Extended Power Uprate (EPU)Large Break Loss of Cooling Accident (LBLOCA) PCT of 2115'F and EPU Small Break LOCA(SBLOCA) PCT of 1231'F for Turkey Point Units 3 and 4.FPL letter L-2014-037 (Reference 2), submitted a 30-Day Special Report documenting an errorin the LBLOCA EM in the calculation of the burst strain performed by the HOTSPOT code(Reference 2). The impact of this error resulted in an estimated PCT impact of +18 °F. Therevised LBLOCA PCT for Turkey Point Units 3 and 4 was 2133 OF with a cumulative change of890F due to the EM error. The SBLOCA EM is not affected by the identified error.FPL letter L-2014-084 (Reference 1), submitted a 30-Day Special Report documenting severalLBLOCA EM errors. One issue was related to the grid heat transfer enhancement calculationwhich potentially affected the heat transfer at gridded elevations. Another error was introduceddue to a change in the methodology used to calculate grid blockage ratio and porosity. Themethodology change resulted in a change to the grid inputs which affected the heat transfer inthe core during a LBLOCA. In addition, deficiencies were identified in the vessel Section 7 Mid-Level Elevation modeling documentation. The LBLOCA EM errors and documentationdeficiencies had a negligible effect on LBLOCA analysis results, leading to an estimated PCTimpact of 0°F. The 30-Day Special Report also reported the estimated PCT impact of +18 OFdue to an error in the LBLOCA EM previously reported by FPL letter L-2014-037. The revisedLBLOCA PCT for Turkey Point Units 3 and 4 was 2133 OF with a cumulative change of 89°F dueto the EM error.FPL letters L-2014-077 (Reference 3) and L-2014-302 (Reference 4) submitted a 30-DaySpecial Report for Units 3 and 4 respectively. The LBLOCA PCT reported in the 30 -Day specialreport removed the 120F mixed core penalty no longer applicable for Unit 3 Cycle 27 and Unit 4Cycle 28 and future cycles with only 15x1 5 Upgraded fuel assemblies. The SBLOCA PCT wasnot affected by the mixed core penalty.FPL letter L-2014-359 (Reference 5) submitted a 30-Day Special Report for Turkey Point Units 3and 4 documenting an error in the LBLOCA EM in the calculation of decay heat in theWCOBRA/TRAC code. The correction of this error resulted in an estimated impact of +3 °F onLBLOCA PCT for Turkey Point Units 3 and 4. The SBLOCA EM was not affected by theidentified errors.By letter dated March 9, 2015, Westinghouse identified several errors in the SBLOCA EM notpreviously discussed. Two errors were associated with the NOTRUMP computer code (reactorcoolant system response model). One error was related to the fuel rod gap conductance model.Another error was identified in the calculation of the radiation heat transfer coefficient within thefuel rod model. Other errors were identified in the pre-departure from nucleate boiling (pre-DNB)cladding surface heat transfer coefficient calculation in the SBLOCTA code (cladding heat-upcalculations). The SBLOCA EM errors had a negligible effect on small break LOCA analysisresults, leading to an estimated PCT impact of 0°F. The magnitude of these SBLOCA errorsand the resultant cumulative changes and errors for the SBLOCA EM remain below the 50 OF30-day reporting threshold of 10 CFR 50.46(a)(3)(i) and (ii).Table 1 provides the Turkey Point Units 3 and 4 2014 Annual Summary listing all the changesand errors identified by Westinghouse in 2014 in the LBLOCA and SBLOCA EMs. The 2014Turkey Point Units 3 and 4 LBLOCA and SBLOCA PCTs are 2124°F and 1231 'F, respectively.The PCT cumulative changes are 80'F for LBLOCA and 0 °F for SBLOCA, respectively.

L-2015-113Page 3 of 410 CFR 50.46(a)(3)(ii) also requires that a schedule for reanalysis be provided or compliancewith the requirements of the regulation be shown if the error is significant. Compliance with 10CFR 50.46 requirements is demonstrated by total estimated LBLOCA and SBLOCA PCTs of2124°F and 1231'F, respectively, both remaining below the limit of 22000F.Should there be any questions, please contact Mitch Guth, Licensing Manager, at305-246-6698.Very truly yours,Michael KileyVice PresidentTurkey Point Nuclear Plantcc: Regional Administrator, Region II, USNRCSenior Resident Inspector, USNRC, Turkey Point Plant L-2015-113Page 4 of 4TABLE 1Turkey Point Units 3 and 4LBLOCA and SBLOCA PCT 2014 Annual ReportPeak Clad CumulativeLBLOCA Temperature Change2013 10 CFR 50.46 Annual Report (Ref. 1) 2115 OF 71 OFErrors in 2014-Error in Burst Strain Application (Re. 1)+18 0 F +18 OF-Grid Heat Transfer Enhancement Calculation (Ref. 1) 0 0F 0 °F-Changes to Grid Blockage Ratio and Porosity (Ref. 1) 0 OF 0 OF-Vessel Section 7 Mid-Level Elevation Modeling (Ref. 1) 0 OF 0 OF-Decay Group Uncertainty Factors Errors (Ref. 5) +3 OF +3 OF-Temporary Mixed Core Penalty Removed (Ref. 3)(Ref. 4) -12 OF -12 OF2014 10 CFR 50.46 Annual Report 2124 OF 80 OFSBLOCA2013 10 CFR 50.46 Annual Report (Ref, 1) 1231 OF 0 OFErrors in 2014-Fuel Rod Gap Conductance (Ref. 6) 0 OF 0 OF-Radiation Heat Transfer Model (Ref. 6) 0 OF 0 OF-SBLOCTA Pre-DNB Cladding Surface Area Heat TransferCoefficient (Ref. 6) 0 OF 0 OF2014 10 CFR 50.46 Annual Report1231 OF 0 OF