ML17179A149

Duane Arnold - Submittal of 10 CFR 50.46 30-Day Special Report of Changes in Peak Cladding Temperature

ML17179A149
Person / Time
Site:	Duane Arnold
Issue date:	06/28/2017
From:	Larry Nicholson Florida Power & Light Co, NextEra Energy Duane Arnold
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
L-2017-118
Download: ML17179A149 (3)

Text

U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 NextEra Energy Duane Arnold, LLC Duane Arnold Energy Center Docket No. 50-331 JUN 2 8 2017 L-2017-118 10 CFR 50.46(a)(3)(ii)

Subject:

10 CFR 50.46 30-Day Special Report of Changes in Peak Cladding Temperature for the Duane Arnold Energy Center

Reference:

Letter from L. Nicholson (Florida Power & Light Company) to USN RC, "1 0 CFR 50.46 Annual Reporting of Changes to, or Errors in Emergency Core Cooling System Models or Applications," L-2017-014, April17, 2017. In accordance with 10 CFR 50.46(a)(3)(ii), Florida Power & Light acting as agent for NextEra Energy Duane Arnold, LLC (NextEra), hereby provides this 30-day special report regarding changes in the calculated peak cladding temperature (PCT) of the GNF2 fuel design currently utilized at the Duane Arnold Energy Center (DAEC). Our fuel vendor, Global Nuclear Fuels (GNF), has notified NextEra of the potential impact of one newly-identified error in the current Loss-of-Coolant Accident analysis methodology and its application that has occurred subsequent to the referenced annual report. Enclosed is a historical summary of previously reported changes or errors, as well as the potential impact of the new error on the GNF2 fuel design currently utilized at DAEC. This new error, when combined (sum of the absolute magnitudes) with all the applicable PCT changes previously reported for the GNF2 fuel design, results in a cumulative PCT change for DAEC of greater than the 50 °F reporting threshold under 10 CFR 50.46(a)(3)(i). Although this is defined as a "significant change" under 10 CFR 50.46, the actual impact on nuclear safety is negligible, as DAEC has significant margin, over 450 °F, to the regulatory limit of 2200 oF PCT in 10 CFR 50.46(b)(1). Thus, a full re-analysis for GNF2 fuel design is not currently scheduled for the DAEC as a result of these cumulative changes. Florida Power & Light Company 700 Universe Boulevard, Juno Beach, FL 33408 L-2017-118 Page 2 of2 This submittal contains no new commitments or revisions to existing commitments. Larry Nicholson Director, Nuclear Licensing and Regulatory Compliance Enclosure (1) cc: Administrator, Region Ill, USNRC Project Manager, Duane Arnold Energy Center, USNRC Resident Inspector, Duane Arnold Energy Center, USNRC L-2017-118 Enclosure 1 Page 1 of 1 Enclosure 1 Summary Rack-Up Sheet GNF2 Fuel LOCA Margin Summary Sheet -30 Day Report Plant Name: Duane Arnold Energy Center Utility name: NextEra Energy Evaluation Model: GE Hitachi Report, "Duane Arnold Energy Center GNF2 ECCS-LOCA Evaluation," GNF Report 0000-0133-6901-RO, DRF 0000-0133-6885-RO, August 2012 Last Acceptable Evaluation Model Analyzed PCT: A Prior 10 CFR 50.46 Changes or L1PCT Error Corrections-up to Year N-1 B Prior 10 CFR 50.46 Changes or L1PCT Enors Conections -YearN c Current 10 CFR 50.46 Changes 1. Impact of modeling forward and backward leakage paths through the L1PCT bottom of the fuel bundle Absolute Sum of 10 CFR 50.46 L1PCT Changes 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 1730 OF NetPCT Absolute PCT Effect Effect 10 op 50 °F None None -20 °F 20 °F -10 °F 70 °F 1720 °F < 2200 °F