NLS2015011, Annual Report of Changes and Errors in Emergency Core Cooling System Evaluation Models for 2014

Annual Report of Changes and Errors in Emergency Core Cooling System Evaluation Models for 2014

ML15027A331
Person / Time
Site:	Cooper
Issue date:	01/21/2015
From:	Shaw J Nebraska Public Power District (NPPD)
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NLS2015011
Download: ML15027A331 (4)

Text

N Nebraska Public Power District Always there when you need us NLS2015011 50.46(a)(3)(ii)

January 21, 2015 U.S. Nuclear Regulatory Commission Attention: Document Control Desk Washington, D.C. 20555-0001

Subject:

Annual Report of Changes and Errors in Emergency Core Cooling System Evaluation Models for 2014 Cooper Nuclear Station, Docket No. 50-298, DPR-46

References:

1. Letter from David Van Der Kamp, Nebraska Public Power District, to U.S. Nuclear Regulatory Commission, dated August 18, 2008, "Failure to Include Error in Emergency Core Cooling System Evaluation Model in Annual Report for 2006"

2. Letter from David Van Der Kamp, Nebraska Public Power District, to U.S. Nuclear Regulatory Commission, dated September 21, 2011, "10 CFR 50.46(a)(3)(ii) Report"

3. Letter from David Van Der Kamp, Nebraska Public Power District, to U.S. Nuclear Regulatory Commission, dated January 17, 2014, "Annual Report of Changes and Errors in Emergency Core Cooling System Evaluation Models for 2013"

Dear Sir or Madam:

The purpose of this letter is to submit the 2014 annual report of changes or errors in the Emergency Core Cooling System (ECCS) evaluation models pursuant to 10 CFR 50.46(a)(3)(ii) for Cooper Nuclear Station (CNS).

By reference letters I through 3, Nebraska Public Power District (NPPD) previously reported errors in the ECCS evaluation model for GE14 fuel. These errors continue to apply to the ECCS evaluation methodology for 2014. In May 2014, CNS received General Electric Hitachi (GEH) 10 CFR 50.46 Notification Letters 2014-01, 2014-02, 2014-03, and 2014-04 which reported additional changes to the ECCS acceptable evaluation model for GE 14 fuel that result in a net 107F increase in the Peak Cladding Temperature (PCT). Collectively, the errors/changes reported by GEH have a +155°F impact and result in a PCT of 2195°F for GE14 fuel.

COOPER NUCLEAR STATION P.O. Box 98 / Brownville, NE 68321-0098 Telephone: (402) 825-3871 / Fax: (402) 825-5211 www.nppd.com

NLS2015011 Page 2 of 2 By reference 3, NPPD previously reported an error in the ECCS evaluation model for GNF2 fuel. This error continues to apply to the ECCS evaluation methodology for 2014. In May 2014, CNS received GEH 10 CFR 50.46 Notification Letters 2014-01, 2014-02, 2014-03, and 2014-04 which reported additional changes to the ECCS acceptable evaluation model for GNF2 fuel that results in a net 10°F increase in the PCT. Collectively, the errors/changes reported by GEH have a +40'F impact and result in a PCT of 2180'F for GNF2 fuel.

All changes/errors are itemized in the attachment to this letter. CNS continues to comply with the PCT limit of 2200'F specified in 10 CFR 50.46(b)(1) for both GE14 and GNF2 fuel types.

In response to the limited margin to the PCT limit for both GE14 and GNF2 fuel types, CNS is taking additional action by contracting with the fuel vendor to evaluate Maximum Average Planar Linear Heat Generation Rate (MAPLHGR) limit setdowns which will reduce the PCT.

This activity is a limited scope reanalysis which will determine MAPLHGR limit setdowns and incorporate all errors/changes currently applicable to the ECCS evaluation models for GE 14 and GNF2 fuel types. This work has been authorized and is expected to be completed by the fuel vendor by May 2015 and implemented at CNS by July 2015.

This letter makes no regulatory commitments.

If you have any questions regarding this report, please contact Jeremy Custer, Reactor and Fuels Engineering Supervisor, at (402) 825-5653.

Sincerely, i~m Shaw Licensing Manager

/lb

Attachment:

Changes/Errors in Emergency Core Cooling System Evaluation Models for 2014 cc: Regional Administrator w/attachment USNRC - Region IV Cooper Project Manager w/attachment USNRC - NRR Project Directorate IV-1 Senior Resident Inspector w/attachment USNRC - CNS NPG Distribution w/attachment CNS Records w/attachment

NLS2015011 Attachment Page 1 of 2 Changes/Errors in Emergency Core Cooling System Evaluation Models for 2014 Nebraska Public Power District - Cooper Nuclear Station GE 14 Fuel GE Hitachi Date Subject PCT Impact 10 CFR 50.46 (OF)

Notification Letter 2006-01 7/28/06 Impact of Top Peaked Power 0°F Shape for Small Break Loss of Coolant Accident Analysis 2011-02 9/2/11 Impact of Database Error for Heat +350 F Deposition on the Peak Cladding Temperature (PCT) for IOxl 0 Fuel Bundles 2011-03 9/2/11 Impact of Updated Formulation +95 0 F for Gamma Heat Deposition to Channel Wall for 9x9 and IOx 10 Fuel Bundles 2012-01 11/29/12 PRIME Fuel Properties +150 F Implementation for Fuel Rod Thermal/Mechanical Performance, Replacing GESTR Fuel Properties 2014-01 5/21/14 SAFER04A Version E4 - 0°F Maintenance Update Changes 2014-02 5/21/14 SAFER04A Version E4 - Mass +100 F Non-Conservatism 2014-03 5/21/14 SAFER04A Version E4 - +20°F Minimum Core Differential Pressure Model 2014-04 5/21/14 SAFER04A Version E4 - -20°F Bundle/Lower Plenum Counter Current Flow Limitation Head 1 Total = +155 0F PCT at beginning of 2014 = 2185°F PCT at end of 2014 = 2195°F

NLS2015011 Attachment Page 2 of 2 GNF2 Fuel GE Hitachi Date Subject PCT Impact 10 CFR 50.46 (OF)

Notification Letter 2012-01 11/29/12 PRIME Fuel Properties +30°F Implementation for Fuel Rod Thermal/Mechanical Performance, Replacing GESTR Fuel Properties 2014-01 5/21/14 SAFER04A Version E4 - 0°F Maintenance Update Changes 2014-02 5/21/14 SAFER04A Version E4 - Mass +10°F Non-Conservatism 2014-03 5/21/14 SAFER04A Version E4 - +20°F Minimum Core Differential Pressure Model 2014-04 5/21/14 SAFER04A Version E4 - -20°F Bundle/Lower Plenum Counter Current Flow Limitation Head Total = +40'F PCT at beginning of 2014 = 2170'F PCT at end of 2014 = 2180TF