NRC 2016-0015, Large Break Loss-of-Coolant Accident Margin Summary Sheet - 30-Day Report

Large Break Loss-of-Coolant Accident Margin Summary Sheet - 30-Day Report

ML16097A193
Person / Time
Site:	Point Beach
Issue date:	04/06/2016
From:	Woyak B Point Beach
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC 2016-0015
Download: ML16097A193 (3)

Text

April 6, 2016 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 Large Break Loss-of-Coolant Accident Margin Summary Sheet-30-Day Report NRC 2016-0015 10 CFR 50.46(a)(3)(ii)

In accordance with 10 CFR 50.46(a)(3)(ii), NextEra Energy Point Beach (NextEra), LLC, is submitting this 30-day report for the Point Beach Nuclear Plant (PBNP) Units 1 and 2 for the emergency core cooling system (ECCS) analysis performed by Westinghouse Electric Company, LLC. The following 30-day report pertaining to the application of the Westinghouse large break loss of coolant accident (LBLOCA) evaluation model is provided pursuant to 10 CFR 50.46(a)(3)(ii).

The Enclosure describes the ECCS evaluation model changes and errors to the large break loss of coolant accident (LOCA). The Table provides the large break LOCA peak cladding temperatures margin summary.

This submittal contains no new commitments or revisions to existing commitments.

Sincerely, NextEra Energy Point Beach, LLC 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, 66} 0 Nuclear R<;>ad; Two Rivers, WI 54241 I i

ENCLOSURE NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 Emergency core cooling system (ECCS) analyses for Point Beach Units 1 and 2 are performed by Westinghouse Electric Company, LLC. The following 30-day report pertaining to the application of the Westinghouse large break loss of coolant accident (LBLOCA) evaluation model is provided pursuant to 10 CFR 50.46(a)(3)(ii). A summary of the calculated peak cladding temperature (PCT) changes for LBLOCA is provided in the Table.

LARGE BREAK LOCA ECCS EVALUATION MODEL CHANGES AND ERRORS Error in Use of ASME Steam Tables The steam table applicable to steam/gas is used to determine the upper head fluid temperature.

However, the water in the upper head is in the subcooled liquid state during normal operation (and the steady-state calculation). Therefore, the steam table applicable to liquid should be used to determine the upper head fluid temperature.

The effect was evaluated and the estimated PCT impact is 0 oF for Point Beach Units 1 and 2.

Previous LBLOCA PCT changes are documented in Reference 1. The Table summarizes the estimated impact of the changes/errors on the Point Beach Units 1 and 2 LBLOCA PCT, along with the cumulative effect of absolute PCT changes for both Point Beach Units. The limiting LBLOCA PCT with the estimated effect of all the changes/errors is 2185 oF and 2058 oF for Units 1 and 2, respectively. With the impact of all changes/errors, Point Beach Units 1 and Unit 2 continue to comply with the 10 CFR 50.46 acceptance criterion for PCT of:::; 2200 °F.

Proposed Schedule The schedule for LBLOCA re-analyses is as provided previously in Reference 2.

References 1 NextEra Energy Point Beach, LLC letter to NRC, dated March 22, 2016, "Point Beach Nuclear Plant, Units 1 and 2, 10 CFR 50.46 Annual Report" (ML16082A296) 2 NextEra Energy Point Beach, LLC letter to NRC, dated March 1, 2013, "Thermal Conductivity Degradation Impact on Large Break Loss of Coolant Accident Analyses with ASTRUM Response to Request for Additional Information" (ML13063A289) l J. \\

i Page 1 of 2

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TABLE LARGE BREAK LOCA MARGIN

SUMMARY

SHEET-30-DAY REPORT Plant Name:

Point Beach Units 1 and 2 Utility Name:

NextEra Energy Evaluation Model:

Westinghouse Realistic Large Break LOCA Evaluation Model using ASTRUM.

(WCAP-16009-P-A)

Evaluation Model PCT (Unit 11Unit 2):

A Prior 10 CFR 50.46 Changes or t1PCT Errors Corrections-up to Year 2015 B

Prior 1 0 CFR 50.46 Changes or t1PCT Errors Correction-Year 2016 c

10 CFR 50.46 Changes in Year 2016 Since Item B Error in ASME Steam Table Use t1PCT t1PCT 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 analysis Page 2 of 2 Net PCT Effect Absolute PCT Effect Unit 11Unit 2 Unit 11Unit 2

+21 0°FI+248°F 210°FI340°F None None 0 OF I 0 OF 0 OF I 0 OF 2185 °F/2058 °F < 2200 OF

April 6, 2016 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 Large Break Loss-of-Coolant Accident Margin Summary Sheet-30-Day Report NRC 2016-0015 10 CFR 50.46(a)(3)(ii)

In accordance with 10 CFR 50.46(a)(3)(ii), NextEra Energy Point Beach (NextEra), LLC, is submitting this 30-day report for the Point Beach Nuclear Plant (PBNP) Units 1 and 2 for the emergency core cooling system (ECCS) analysis performed by Westinghouse Electric Company, LLC. The following 30-day report pertaining to the application of the Westinghouse large break loss of coolant accident (LBLOCA) evaluation model is provided pursuant to 10 CFR 50.46(a)(3)(ii).

The Enclosure describes the ECCS evaluation model changes and errors to the large break loss of coolant accident (LOCA). The Table provides the large break LOCA peak cladding temperatures margin summary.

This submittal contains no new commitments or revisions to existing commitments.

Sincerely, NextEra Energy Point Beach, LLC 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, 66} 0 Nuclear R<;>ad; Two Rivers, WI 54241 I i

ENCLOSURE NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 Emergency core cooling system (ECCS) analyses for Point Beach Units 1 and 2 are performed by Westinghouse Electric Company, LLC. The following 30-day report pertaining to the application of the Westinghouse large break loss of coolant accident (LBLOCA) evaluation model is provided pursuant to 10 CFR 50.46(a)(3)(ii). A summary of the calculated peak cladding temperature (PCT) changes for LBLOCA is provided in the Table.

LARGE BREAK LOCA ECCS EVALUATION MODEL CHANGES AND ERRORS Error in Use of ASME Steam Tables The steam table applicable to steam/gas is used to determine the upper head fluid temperature.

However, the water in the upper head is in the subcooled liquid state during normal operation (and the steady-state calculation). Therefore, the steam table applicable to liquid should be used to determine the upper head fluid temperature.

The effect was evaluated and the estimated PCT impact is 0 oF for Point Beach Units 1 and 2.

Previous LBLOCA PCT changes are documented in Reference 1. The Table summarizes the estimated impact of the changes/errors on the Point Beach Units 1 and 2 LBLOCA PCT, along with the cumulative effect of absolute PCT changes for both Point Beach Units. The limiting LBLOCA PCT with the estimated effect of all the changes/errors is 2185 oF and 2058 oF for Units 1 and 2, respectively. With the impact of all changes/errors, Point Beach Units 1 and Unit 2 continue to comply with the 10 CFR 50.46 acceptance criterion for PCT of:::; 2200 °F.

Proposed Schedule The schedule for LBLOCA re-analyses is as provided previously in Reference 2.

References 1 NextEra Energy Point Beach, LLC letter to NRC, dated March 22, 2016, "Point Beach Nuclear Plant, Units 1 and 2, 10 CFR 50.46 Annual Report" (ML16082A296) 2 NextEra Energy Point Beach, LLC letter to NRC, dated March 1, 2013, "Thermal Conductivity Degradation Impact on Large Break Loss of Coolant Accident Analyses with ASTRUM Response to Request for Additional Information" (ML13063A289) l J. \\

i Page 1 of 2

l..

TABLE LARGE BREAK LOCA MARGIN

SUMMARY

SHEET-30-DAY REPORT Plant Name:

Point Beach Units 1 and 2 Utility Name:

NextEra Energy Evaluation Model:

Westinghouse Realistic Large Break LOCA Evaluation Model using ASTRUM.

(WCAP-16009-P-A)

Evaluation Model PCT (Unit 11Unit 2):

A Prior 10 CFR 50.46 Changes or t1PCT Errors Corrections-up to Year 2015 B

Prior 1 0 CFR 50.46 Changes or t1PCT Errors Correction-Year 2016 c

10 CFR 50.46 Changes in Year 2016 Since Item B Error in ASME Steam Table Use t1PCT t1PCT 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 analysis Page 2 of 2 Net PCT Effect Absolute PCT Effect Unit 11Unit 2 Unit 11Unit 2

+21 0°FI+248°F 210°FI340°F None None 0 OF I 0 OF 0 OF I 0 OF 2185 °F/2058 °F < 2200 OF