ML13247A172

Donald C. Cook Nuclear Plant Units 1 and 2 Annual Report of Loss-of-Coolant Accident Evaluation Model Changes

ML13247A172
Person / Time
Site:	Cook
Issue date:	08/30/2013
From:	Gebbie J P Indiana Michigan Power Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
AEP-NRC-2013-32
Download: ML13247A172 (7)

Text

INDIANA Indiana Michigan PowerMICHIGAN Cook Nuclear PlantHWER One Cook PlaceBridgman, M1 49106A unit of American Electric Power India naMichigan Power.com August 30, 2013 AEP-NRC-2013-32 10 CFR 50.46Docket Nos.: 50-31550-316U. S. Nuclear Regulatory Commission ATTN: Document Control DeskWashington, DC 20555-0001 Donald C. Cook Nuclear Plant Units 1 and 2ANNUAL REPORT OF LOSS-OF-COOLANT ACCIDENTEVALUATION MODEL CHANGES

References:

1. Letter from J. P. Gebbie, Indiana Michigan Power Company (I&M), to U. S.Nuclear Regulatory Commission (NRC), "Response to Information RequestPursuant to 10 CFR 50.54(f)

Related to the Estimated Effect on Peak CladdingTemperature Resulting from Thermal Conductivity Degradation on theWestinghouse-Furnished Realistic Emergency Core Cooling System Evaluation,"

AEP-NRC-2012-13, dated March 19, 2012, (ADAMS Accession No.ML 12088A104).

2. Letter from M. H. Carlson, I&M, to NRC, "Donald C. Cook Nuclear Plant Units 1and 2 Response to Request for Information 10 CFR 50.46 Report for Emergency Core Cooling System Model Change or Error Associated with ThermalConductivity Degradation,"

dated June 11, 2012, (ADAMS Accession No. ML12173A025).

3. Letter from P. S. Tam, NRC, to Lawrence J. Weber, I&M, "D. C. Cook NuclearPlant (DCCNP),

Units 1 and 2 -Closeout of Information Request Pursuant to50.54(f)

Related to the Estimated Effect on Peak Cladding Temperature Resulting from Thermal Conductivity Degradation in the Westinghouse-Furnished Realistic Emergency Core Cooling System Evaluation,"

dated April 2, 2012,(ADAMS Accession No. ML 12088A376).

4. Letter from T. J. Wengert, NRC, to L. J. Weber, I&M, "Donald C. Cook NuclearPlant, Units 1 and 2 -Evaluation of Report concerning Significant Emergency Core Cooling System Evaluation Model Error Related to Nuclear Fuel ThermalConductivity Degradation (TAC NOS. ME8322 and ME8323),"

datedMarch 7, 2013, (ADAMS Accession No. ML1 3077A1 37).

U.S. Nuclear Regulatory Commission AEP-NRC-2013-32 Page 2Pursuant to 10 CFR 50.46, Indiana Michigan Power Company, the licensee forDonald 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) forCNP Unit 1 and Unit 2. CNP is providing, as an enclosure to this letter, the Unit 1 and Unit 2Large Break and Small Break LOCA Analyses-of-Record PCT values and error assessments forcalendar year 2012.The impacts to Large Break LOCA PCT due to fuel pellet thermal conductivity degradation werepreviously reported to the Nuclear Regulatory Commission (NRC) in Reference 1 andsupplemented by Reference

2. NRC staff review and acceptance of the impact to PCT due tofuel pellet thermal conductivity degradation was documented in Reference

4. These impacts tothe LOCA analyses are discussed in the enclosure, and are included on the PCT reporting sheets.Several other changes were made to the Large Break LOCA and Small Break LOCA evaluation models during the reporting period. The specific details of these changes were evaluated ashaving no impact on the calculated PCTs. Since there was no PCT impact due to thesechanges, they are not included in the PCT reporting sheets.There are no new or revised commitments in this letter. Should you have any questions, pleasecontact Mr. Michael K. Scarpello, Regulatory Affairs Manager, at (269) 466-2649.

Sincerely, Joel P. GebbieSite Vice President DMB/kmh

Enclosure:

Donald C. Cook Nuclear Plant Units 1 and 2, Large and Small BreakLoss-of-Coolant Accident Peak Clad Temperature Summaryc: J. T. King, MPSCS. M. Krawec, AEP Ft. Wayne, w/o enclosures MDEQ -RMD/RPSNRC Resident Inspector C. D. Pederson, NRC Region IIIT. J. Wengert, NRC Washington, DC ENCLOSURE TO AEP-NRC-2013-32 DONALD C. COOK NUCLEAR PLANT UNITS 1 AND 2LARGE AND SMALL BREAK LOSS-OF-COOLANT ACCIDENTPEAK CLAD TEMPERATURE SUMMARYAbbreviations:

CNP Donald C. Cook Nuclear PlantOF degrees Fahrenheit ECCS emergency core cooling systemEM evaluation methodology FdH nuclear enthalpy rise hot channel factorFQ heat flux hot channel factorHHSI high head safety injection (Safety Injection System at CNP)I&M Indiana Michigan Power CompanyLOCA loss of coolant accidentMWt megawatts

-thermalNRC Nuclear Regulatory Commission PCT peak cladding temperature RHR Residual Heat RemovalSGTP steam generator tube pluggingTCD thermal conductivity degradation Summary:By letter dated March 19, 2012, (ADAMS Accession No. ML12088A1 04), and supplemented byletter dated June 11, 2012, (ADAMS Accession No. ML12173A025),

I&M, the licensee for CNPUnits 1 and 2, submitted a report describing the impact of fuel pellet TCD on the Large BreakLOCA ECCS evaluation model, and an estimate of the effect on the predicted PCT for CNPUnits 1 and 2. This report was submitted pursuant to Title 10 of the Code of FederalRegulations (10 CFR) Part 50, Section 50.46, Paragraph (a)(3), and referred to a letter fromWestinghouse 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. ML1 3077A1 37).A new small break LOCA analysis of record was implemented for CNP Unit 1 in 2012. Therevised small break LOCA was provided to the NRC by letter dated August 31, 2012 (ADAMSAccession No. ML12256A685).

The enclosure to the letter provides a report of the revisedanalysis.

The results of the revised small break LOCA analysis conform to the emergency corecooling system acceptance criteria of 10 CFR 50.46. The calculated peak cladding temperature of 17250F is below the 10 CFR 50.46 limit of 22001F.The following pages summarize the impact of TCD, peaking factor burndown, and plantmodification evaluations on the CNP Units 1 and 2 Large Break LOCA analyses of record. Inaddition, pages are included that summarize the small break LOCA PCT analyses of record forCNP Units 1 and 2.

Enclosure to AEP-NRC-2013-32 Page 2CNP UNIT 1LOCA Peak Clad Temperature Summary for ASTRUM Best Estimate Large BreakEvaluation Model: ASTRUM (2004)FQ= 2.15 FdH = 1.55 SGTP = 10%(a) Break Size: SplitAnalysis Date: November 20, 2007LICENSING BASISAnalysis-of-Record MARGIN ALLOCATIONS (Delta PCT)A. PREVIOUS 10 CFR 50.46 ASSESSMENTS

1. NonePCT = 2128°FB.C.D.PLANNED PLANT MODIFICATION EVALUATIONS NEW 10 CFR 50.46 ASSESSMENTS OTHER0OF-381 °F(a)3840F(a)0OFPCT = 2131°FLICENSING BASIS PCT + MARGIN ALLOCATIONS Notes:a. These assessments are coupled via an evaluation of burnup effects which includethermal conductivity degradation, 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 datedMarch 19, 2012, (ADAMS Accession No. ML12088A104),

and supplemented by letterdated June 11, 2012, (ADAMS Accession No. ML12173A025),

and subsequently foundacceptable by NRC letter dated March 7, 2013 (ADAMS Accession No. ML1 3077A1 37).

Enclosure to AEP-NRC-2013-32 Page 3CNP UNIT 1LOCA Peak Clad Temperature Summary for Appendix K Small BreakEvaluation Model: NOTRUMPFQ=2.32 FdH=1.55 SGTP=10%

3.25 inch cold leg breakAnalysis Date: January 6, 2012Notes: 3304 MWt (plus 0.34% calorimetric uncertainty)

LICENSING BASISAnalysis-of-Record PCT = 1725°FMARGIN ALLOCATIONS (Delta PCT)A. PREVIOUS 10 CFR 50.46 ASSESSMENTS

1. NoneB. PLANNED PLANT MODIFICATION EVALUATIONS C. NEW 10 CFR 50.46 ASSESSMENTS D. OTHERLICENSING BASIS PCT + MARGIN ALLOCATIONS 0OF0OF0OF0OFPCT = 1725°F Enclosure to AEP-NRC-2013-32 Page 4CNP UNIT 2LOCA Peak Clad Temperature Summary for ASTRUM Best Estimate Large BreakEvaluation Model: ASTRUM (2004)FQ = 2.335 FdH = 1.644 SGTP = 10%(a) Break Size: SplitAnalysis Date: February 9, 2009LICENSING BASISAnalysis-of-Record PCT = 2107°FMARGIN ALLOCATIONS (Delta PCT)A. PREVIOUS 10 CFR 50.46 ASSESSMENTS

1. NoneB.PLANNED PLANT MODIFICATION EVALUATIONS C. NEW 10 CFR 50.46 ASSESSMENTS D. OTHERLICENSING BASIS PCT + MARGIN ALLOCATIONS 0OF-2390F(a)730F(a)0OFPCT = 19410FNotes:a. These assessments are coupled via an evaluation of burnup effects which includethermal conductivity degradation, 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 datedMarch 19, 2012, (ADAMS Accession No. ML12088A104),

and supplemented by letterdated June 11, 2012, (ADAMS Accession No. ML12173A025),

and subsequently foundacceptable by NRC letter dated March 7, 2013 (ADAMS Accession No. ML13077A137).

Enclosure to AEP-NRC-2013-32 Page 5CNP UNIT 2LOCA Peak Clad Temperature Summary for Appendix K Small BreakEvaluation Model: NOTRUMPFQ= 2.32 FdH= 1.62 SGTP = 10% 4 inch cold leg breakAnalysis Date: April 25, 2011Notes: 3600 MWtLICENSING BASISAnalysis-of-Record PCT = 1274°F (a)MARGIN ALLOCATIONS (Delta PCT)A. PREVIOUS 10 CFR 50.46 ASSESSMENTS

1. None 0°FB. PLANNED PLANT MODIFICATION EVALUATIONS 0OFC. NEW 10 CFR 50.46 ASSESSMENTS 0OFD. OTHER 0°FLICENSING BASIS PCT + MARGIN ALLOCATIONS PCT = 1274°FNotes:a. The 3600 MWt power level used in this analysis bounds the Unit 2 3468 MWt steadystate power limit in the operating license.