AEP-NRC-2014-62, Annual Report of Loss-of-Coolant Accident Evaluation Model Changes
| ML14245A016 | |
| Person / Time | |
|---|---|
| Site: | Cook  |
| Issue date: | 08/28/2014 |
| From: | Gebbie J Indiana Michigan Power Co |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| AEP-NRC-2014-62 | |
| Download: ML14245A016 (7) | |
Text
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ICHIGAN A unit of American Electric Power Indiana Michigan Power Cook Nuclear Plant One Cook Place Bridgman, Ml 49106 IndianaMichiga nPower.c om AEP-NRC-2014-62 10 CFR 50.46 August 28, 2014 Docket Nos.: 50-315 50-316 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Donald C. Cook Nuclear Plant Units 1 and 2 ANNUAL REPORT OF LOSS-OF-COOLANT ACCIDENT EVALUATION MODEL CHANGES Pursuant to 10 CFR 50.46, Indiana Michigan Power Company (I&M),
the licensee for Donald C. Cook Nuclear Plant (CNP), is transmitting an annual report of loss-of-coolant accident (LOCA) evaluation model changes affecting the peak cladding temperature (PCT) for CNP Unit 1 and Unit 2. I&M is providing, as an enclosure to this letter, the Unit 1 and Unit 2 Large Break and Small Break LOCA Analyses-of-Record PCT values and error assessments for calendar year 2013.
There are no new or revised commitments in this letter. Should you have any questions, please contact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at (269) 466-2649.
Sincerely, Joel P. Gebbie Site Vice President DMB/kmh
Enclosure:
Donald C. Cook Nuclear Plant Units 1 and 2, Large and Small Break Loss-of-Coolant Accident Peak Clad Temperature Summary c:
M. L. Chawla, NRC Washington, D.C.
J. T. King, MPSC MDEQ - RMD/RPS NRC Resident Inspector C. D. Pederson, NRC Region III A. J. Williamson, AEP Ft. Wayne, w/o enclosures
ENCLOSURE TO AEP-NRC-2014-62 DONALD C. COOK NUCLEAR PLANT UNITS 1 AND 2 LARGE AND SMALL BREAK LOSS-OF-COOLANT ACCIDENT PEAK CLAD TEMPERATURE
SUMMARY
Abbreviations:
ADAMS Agencywide Document Access and Management System CNP Donald C. Cook Nuclear Plant OF degrees Fahrenheit ECCS emergency core cooling system EM evaluation methodology FdH nuclear enthalpy rise hot channel factor FQ heat flux hot channel factor I&M Indiana Michigan Power Company LOCA loss of coolant accident MWt megawatts - thermal NRC Nuclear Regulatory Commission PBOT power limit at bottom part of reactor PCT peak cladding temperature PMID power limit at middle part of reactor SGTP steam generator tube plugging TCD thermal conductivity degradation Summary:
By letter dated March 19, 2012, (ADAMS Accession No. ML12088A104), and supplemented by letter dated June 11, 2012, (ADAMS Accession No. ML12173A025), I&M, the licensee for CNP Units 1 and 2, submitted a report describing the impact of fuel pellet TCD on the Large Break LOCA ECCS evaluation model, and an estimate of the effect on the predicted PCT for CNP Units 1 and 2.
This report was submitted pursuant to Title 10 of the Code of Federal Regulations (10 CFR) Part 50, Section 50.46, Paragraph (a)(3), and referred to a letter from Westinghouse Electric Company dated March 7, 2012 (ADAMS Accession No. ML12072A035).
The report was subsequently found to be acceptable by NRC letter dated March 7, 2013 (ADAMS Accession No. ML13077A137).
By letter dated August 30, 2013 (ADAMS Accession No. ML13247A174), I&M, the licensee for CNP Unit 1, submitted a report describing the impact of Revised Heat Transfer Multiplier Distributions on the predicted PCT for CNP Unit 1. This report was submitted pursuant to 10 CFR Part 50, Section 50.46, Paragraph (a)(3).
By Westinghouse letter LTR-LIS-13-360, "D. C. Cook Units 1 and 2 10 CFR 50.46 Report for Revised Heat Transfer Multiplier Distributions," dated July 31, 2013, Westinghouse Electric Company notified I&M, of significant errors in the EM for the Large-Break (LB) LOCA analysis of record for CNP Unit 1.
By Westinghouse letter LTR-LIS-13-406, "Additional Information on the Evaluation of Revised Heat Transfer Multiplier Distributions," dated August 14, 2013, Westinghouse Electric Company
Enclosure to AEP-NRC-2014-62 Page 2 provided I&M additional detail on the nature of the errors and the corrections made.
As documented in the subsequent temperature summary sheets the error results in a benefit to the calculated PCT.
The following pages summarize the impact of TCD, peaking factor burndown, heat transfer multiplier distribution revisions, and plant modification evaluations on the CNP Units 1 and 2 LB LOCA analyses of record.
In addition, pages are included that summarize the small break LOCA PCT analyses of record for CNP Units 1 and 2.
Enclosure to AEP-NRC-2014-62 Page 3 CNP UNIT 1 LOCA Peak Clad Temperature Summary for ASTRUM Best Estimate Large Break Evaluation Model: ASTRUM (2004)
FQ= 2.15 FdH = 1.55 SGTP = 10%(a)
Break Size: Split Analysis Date: November 20, 2007 LICENSING BASIS Analysis-of-Record MARGIN ALLOCATIONS (Delta PCT)
A.
PREVIOUS 10 CFR 50.46 ASSESSMENTS B.
PLANNED PLANT MODIFICATION EVALUATIONS
- 1. PBOT/PMID Evaluation for Cycle 25 C.
NEW 10 CFR 50.46 ASSESSMENTS
- 1. Revised Heat Transfer Multiplier Distributions D.
OTHER LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 2128°F 384°F(a)
-381 °F(a) 140F
-550F I OF PCT = 2090°F Notes:
- a. These assessments are coupled via an evaluation of burnup effects which include TCD, peaking factor burndown and design input changes (e.g., reduction in the maximum allowed steam generator tube plugging from 10% to 2% and maximum FdH reduced to 1.545). Evaluation details provided in a letter dated March 19, 2012, (ADAMS Accession No. ML12088A104), and supplemented by letter dated June 11, 2012, (ADAMS Accession No. ML12173A025), and subsequently found acceptable by NRC letter dated March 7, 2013 (ADAMS Accession No. ML13077A137).
Enclosure to AEP-NRC-2014-62 Page 4 L
CNP UNIT 1 LOCA Peak Clad Temperature Summary for Appendix K Small Break Evaluation Model:
NOTRUMP FQ=2.32 FdH=1.55 SGTP=10%
3.25 inch cold leg break Analysis Date: January 6, 2012 Notes: 3304 MWt (plus 0.34% calorimetric uncertainty)
LICENSING BASIS Analysis-of-Record PCT = 1 MARGIN ALLOCATIONS (Delta PCT)
A.
PREVIOUS 10 CFR 50.46 ASSESSMENTS
- 1.
None B.
PLANNED PLANT MODIFICATION EVALUATIONS C.
NEW 10 CFR 50.46 ASSESSMENTS D.
OTHER LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 1 725 0F O0F 00F 00F 00F 725 0F
Enclosure to AEP-NRC-2014-62 Page 5 CNP UNIT 2 LOCA Peak Clad Temperature Summary for ASTRUM Best Estimate Large Break Evaluation Model: ASTRUM (2004)
FQ-= 2.335 FdH = 1.644 SGTP = 10%(a.)
Break Size: Split Analysis Date: February 9, 2009 LICENSING BASIS Analysis-of-Record PCT = 2107*F MARGIN ALLOCATIONS (Delta PCT)
A.
PREVIOUS 10 CFR 50.46 ASSESSMENTS B.
PLANNED PLANT MODIFICATION EVALUATIONS C.
NEW 10 CFR 50.46 ASSESSMENTS
- 1. Changes to Grid Blockage Ratio and Porosity
- 2. Revised Heat Transfer Multiplier Distributions D.
OTHER LICENSING BASIS PCT + MARGIN ALLOCATIONS 73017(a)
-2390F(a) 160F
-30F 0OF PCT = 1954°F Notes:
- a. These assessments are coupled via an evaluation of burnup effects which include TCD, peaking factor burndown and design input changes (e.g., reduction in the maximum allowed steam generator tube plugging from 10% to 1% and maximum FdH reduced to 1.61). Evaluation details provided in a letter dated March 19, 2012, (ADAMS Accession No. ML12088A104), and supplemented by letter dated June 11, 2012, (ADAMS Accession No. ML12173A025), and subsequently found acceptable by NRC letter dated March 7, 2013 (ADAMS Accession No. ML13077A137).
Enclosure to AEP-NRC-2014-62 Page 6 CNP UNIT 2 LOCA Peak Clad Temperature Summary for Appendix K Small Break Evaluation Model: NOTRUMP FQ-2.32 FdH= 1.62 SGTP = 10% 4 inch cold leg break Analysis Date: April 25, 2011 Notes: 3600 MWt LICENSING BASIS Analysis-of-Record PCT = 1274°F (a)
MARGIN ALLOCATIONS (Delta PCT)
A.
PREVIOUS 10 CFR 50.46 ASSESSMENTS
- 1.
None 0°F B.
PLANNED PLANT MODIFICATION EVALUATIONS 0°F C.
NEW 10 CFR 50.46 ASSESSMENTS 00F D.
OTHER 0°F LICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 1274°F Notes:
- a. The 3600 MWt power level used in this analysis bounds the Unit 2 3468 MWt steady state power limit in the operating license.