NRC 2013-0043, CFR 50.46 Annual Report
| ML13169A261 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 06/18/2013 |
| From: | Millen M Point Beach |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NRC 2013-0043 | |
| Download: ML13169A261 (5) | |
Text
NEXTera ENERGY &
POINT BEACH June 18, 2013 NRC 2013-0043 10 CFR 50.46(a)(3)(ii)
U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Point Beach Nuclear Plant, Units 1 and 2 Dockets 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 10 CFR 50.46 Annual Report In accordance with 10CFR50.46(a)(3)(ii), NextEra Energy Point Beach (NextEra), LLC, is submitting this annual report of changes to, and errors discovered in, emergency core cooling system (ECCS) evaluation models for Point Beach Nuclear Plant (PBNP), Units 1 and 2. This letter provides a summary of ECCS evaluation model changes and errors identified for the Year 2012.
The Enclosure describes the ECCS evaluation model changes and errors for the large and small break loss of coolant accident (LOCA). Table 1 provides the large break LOCA margin summary sheet for 2012. Table 2 provides the small break LOCA margin summary sheet for 2012.
This submittal contains no new commitments or revisions to existing commitments.
Very truly yours, NextEra Energy Point Beach, LLC
/
Michael Millen Licensing Manager Point Beach Nuclear Plant Enclosure cc: Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC NextEra Energy Point Beach , LLC, 6610 Nuclear Road, Two Rivers, WI 54241
ENCLOSURE NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 10 CFR 50.46 ANNUAL REPORT This annual report of changes to, and errors discovered in, emergency core cooling system (ECCS) evaluation models for Point Beach Nuclear Plant (PBNP) Units 1 and 2, for the Year 2012, is provided pursuant to 10 CFR 50.46(a)(3)(ii) . The report provides a summary of ECCS evaluation model changes and errors identified since the previous annual report (Reference 1). Westinghouse Electric Company is the analysis of record holder for the Point Beach Units 1 and 2 Large Break and Small Break loss of coolant accident (LOCA) analyses. Large Break LOCA analysis is performed using the Westinghouse Realistic Large Break LOCA Evaluation Model using ASTRUM methodology. Small Break LOCA analysis is performed using the Westinghouse Small Break LOCA Evaluation Model with NOTRUMP.
LARGE BREAK LOCA ECCS EVALUATION MODEL CHANGES AND ERRORS There was one change to the LBLOCA due to the thermal conductivity degradation and peaking factor burndown issue, which was previously reported in 30 day report (Reference 2). The following additional 4 changes since the Reference 2 report have been identified and are described below.
- HOTSPOT burst temperature calculation for ZIRLO cladding; This change to correct invalid extrapolation of burst temperature vs. engineering hoop stress table in the HOTSPOT code. The estimated impact of this change is 0 °F.
- HOTSPOT iteration algorithm for calculating the initial fuel pellet average temperature; The HOTSPOT code is updated to correct the iteration algorithm for calculating the initial pellet average temperature. The estimated impact of this change is 0 °F.
- WCOBRAITRAC automated restart process logic error; A minor error was identified in the WCOBRA!TRAC Automated Restart Process (WARP) logic for defining the Double-Ended Guillotine break tables. The estimated impact of this change is 0 °F.
- Rod internal pressure (RIP) calculation; This change is for the resolution of issues related to the sampling of rod internal pressure uncertainties, updating HOTSPOT to consider the effect of transient RIP variations, and generating RIPs at a consistent rod power. The estimated impact of this change is 0 °F.
Table 1 provides a summary of large break LOCA PCT changes for Point Beach Units 1 and 2.
Page 1 of 4
SMALL BREAK LOCA ECCS EVALUATION MODEL CHANGES AND ERRORS The following one change to the Small Break LOCA has been identified and is described below.
- NOTRUMP-EM Evaluation of Fuel Pellet Thermal Conductivity Degradation (TCD): The effect of fuel pellet TCD on PCT using 1985 Westinghouse Small Break LOCA Evaluation Model with NOTRUMP-EM is estimated to be 0 °F.
Table 2 provides a summary of small break LOCA PCT changes for Point Beach Units 1 and 2.
References:
- 1. NRC 2012-0032, J. Costedio (NextEra Energy) to US NRC Document Control Desk, "Point Beach Nuclear Plant, Units 1 and 2, Dockets 50-266 and 50-301, Renewed License Nos. DPR-24 and DPR-27, ECCS Evaluation Model Changes," April27, 2012 (ML12121A007).
- 2. NRC 2012-0038, J. Costedio (NextEra Energy) to US NRC Document Control Desk, "Point Beach Nuclear Plant, Units 1 and 2, Dockets 50-266 and 50-301, Renewed License Nos. DPR-24 and DPR-27, ECCS 30-Day Report for the Thermal Conductivity Degradation Impact on Point Beach Nuclear Plant Units 1 and 2 Large Break Loss of Coolant Accident Analyses with ASTRUM," May30, 2012 (ML12152A101).
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Table 1 LARGE BREAK LOCA MARGIN
SUMMARY
SHEET - 2012 ANNUAL REPORT Plant Name: Point Beach Units 1 and 2 Utility Name: NextEra Energy Evaluation Model: Westinghouse Realistic Large Break LOCA Evaluation Model using ASTRUM.
Evaluation Model PCT (Unit 1/Unit 2):
Absolute PCT Net PCT Effect Effect Unit 1/Unit 2 Unit 1/Unit 2 Prior 10 CFR 50.46 Changes or OoF/OoF A L'lPCT 0°F/0°F Error Corrections- up to Year 2011 Prior 10 CFR 50.46 Changes or B
Errors Corrections- Year 2012 Evaluation of TCD and peaking L'lPCT +151 °F/+285°F 151 °F/285°F factor burndown*
10 CFR 50.46 Changes in Year c 2012 Since Item B HOTSPOT burst temperature OoF/OoF L'lPCT 0°F/0°F calculation for ZIRLO cladding HOTSPOT iteration algorithm for calculating the initial fuel pellet L'lPCT 0°F/0oF 0°F/0°F average temperature WCOBRA/TRAC Automated Restart llPCT 0°F/0oF 0°F/0°F Process Logic Error Rod Internal Pressure (RIP)
L'lPCT OoF/OoF OoF/OoF Calculation Absolute Sum of 10 CFR 50.46 D L'lPCT 151 °F/285°F Changes The sum of the PCT from the most recent analysis using an acceptable evaluation model and the estimates of PCT impact for changes and errors identified since this 2126°F/2095°F < 2200°F analysis
- Previously reported in Reference 2 Page 3 of 4
Table 2 SMALL BREAK LOCA MARGIN
SUMMARY
SHEET- 2012 ANNUAL REPORT Plant Name: Point Beach Units 1 and 2 Utility Name: NextEra Energy Evaluation Model: Westinghouse Small Break LOCA Evaluation Model with NOTRUMP Evaluation Model PCT (Unit 1/Unit 2):
Absolute PCT Net PCT Effect Effect Unit 1/Unit 2 Unit 1/Unit 2 Prior 10 CFR 50.46 Changes or A L1PCT 0°F/0°F 0°F/0°F Error Corrections- up to Year 2011 Prior 10 CFR 50.46 Changes or OoF/OoF B l1PCT 0°F/OoF Errors Corrections - Year 2012 10 CFR 50.46 Changes in Year c 2012 Since Item B NOTRUMP-EM evaluation of fuel L1PCT 0°F/0oF 0°F/0°F pellet TCD Absolute Sum of 10 CFR 50.46 OoF/OoF D L1PCT Changes The sum of the PCT from the most recent analysis using an acceptable evaluation model and the estimates of PCT impact for changes and errors identified since this 1049°F/11 03°F < 2200°F analysis Page 4 of 4