NRC 2012-0032, Annual Report of ECCS Evaluation Model Changes
| ML12121A007 | |
| Person / Time | |
|---|---|
| Site: | Point Beach  |
| Issue date: | 04/27/2012 |
| From: | Jim Costedio Point Beach |
| To: | Office of Nuclear Reactor Regulation, Document Control Desk |
| References | |
| NRC 2012-0032 | |
| Download: ML12121A007 (5) | |
Text
April 27, 2012 POINT BEACH NRC 201 2-0032 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 ECCS Evaluation Model Changes In accordance with 1 OCFR50.46(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 since the previous annual report dated May 1 1, 201 1 to December 31, 201 1. For consistency with fleet practices, annual reports will now be for the preceding calendar year instead of the period from previous annual report to the next annual report. 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 201 1. Table 2 provides the small break LOCA margin summary sheet for 201 1.
There were no changes or errors to the large break or small break LOCA evaluation models during this reporting period that resulted in a change to the calculated peak cladding temperature (PCT) for PBNP.
NextEra is aware of an ECCS evaluation model error being investigated by Westinghouse and will provide an updated 10CFR50.46 letter within 30 days of finalization of that investigation.
NextEra Energy Point Beach, LLC, 6610 Nuclear Road, Two Rivers, WI 54241
Document Control Desk Page 2 This submittal contains no new commitments or revisions to existing commitments.
Very truly yours, NextEra Energy Point Beach, LLC Licensing Manager Point Beach Nuclear Plant Enclosures cc:
Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC
ENCLOSURE I NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 LARGE BREAK LOCA MARGIN
SUMMARY
SHEET FOR 201 1
References:
- 1. NRC 201 1-0050, 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," May 5,201 1.
- 2. T. A. Beltz (USNRC) to L. Meyer (NextEra Energy), "Point Beach Nuclear Plant (PBNP),
Units 1 and 2 - Issuance of License Amendments Regarding Extended Power Uprate (TAC NOS. ME1044 and ME1 045)," May 3,201 1.
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 201 1 is provided pursuant to 1 OCFR50.46(a)(3)(ii). The report provides a summary of ECCS evaluation model changes and errors identified since the previous annual report (Reference 1) until December 31, 201 1. Westinghouse Electric Company is the analysis of record holder for PBNP 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. The 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 were no changes or errors in the Large Break LOCA analysis during this reporting period that resulted in a change to the calculated peak cladding temperature (PCT) for the Point Beach Nuclear Plant (PBNP). Table 1 provides a summary of PCT changes for PBNP Units 1 and 2.
SMALL BREAK LOCA ECCS EVALUATION MODEL CHANGES AND ERRORS The Small Break LOCA was reanalyzed and was approved in 201 1 in amendment No. 241 for Unit 1 and Amendment No. 245 for Unit 2 as part of the EPU approval (Reference 2). There were no changes or errors to the small break LOCA evaluation model during this reporting period that resulted in a change to the calculated PCT for PBNP. Table 2 provides a summary of PCT changes for PBNP Units 1 and 2.
Page 1 of 3
Table 1 LARGE BREAK LOCA MARGIN
SUMMARY
SHEET - 201 I ANNUAL REPORT Plant Name:
Point Beach Units 1 and 2 Utilitv Name:
NextEra Energy Evaluation Model:
Westinghouse Realistic Large Break LOCA Evaluation Model using ASTRUM.
Evaluation Model PCT (Unit 1/Unit 2):
1975 "F11810 OF Prior 10 CFR 50.46 Changes or Error Corrections - up to Year 201 0 APCT Prior 10 CFR 50.46 Changes or Errors Corrections - Year 201 1 10 CFR 50.46 Changes in Year 201 1 Since Item B Absolute Sum of 10 CFR 50.46 Changes APCT APCT 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 Net PCT Effect Unit l/Unit 2 None Absolute PCT Effect Unit l/Unit 2 None Page 2 of 3
Table 2 SMALL BREAK LOCA MARGIN
SUMMARY
SHEET - 2011 ANNUAL REPORT Point Beach Units 1 and 2 Plant Name:
Utilitv Name:
NextEra Energy Evaluation Model:
Westinghouse Small Break LOCA Evaluation Model with NOTRUMP Evaluation Model PCT (Unit I/Unit 2):
1049"F/I 103°F New Small Break LOCA Analysis approved in year 201 1 Prior 10 CFR 50.46 Changes or Errors Corrections - Year 201 1 10 CFR 50.46 Changes in Year 201 1 Since Item B Absolute Sum of 10 CFR 50.46 Changes APCT APCT 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 Net PCT Effect Unit 1IUnit 2 None Unit 11Unit 2 None Page 3 of 3