RA-16-0032, Duke Energy Regulatory Commitment Change Related to Loss of Coolant Accident Reanalysis to Address Fuel Pellet Thermal Conductivity Degradation

Duke Energy Regulatory Commitment Change Related to Loss of Coolant Accident Reanalysis to Address Fuel Pellet Thermal Conductivity Degradation

ML16271A329
Person / Time
Site:	Mcguire, Catawba, McGuire
Issue date:	09/22/2016
From:	Elnitsky J Duke Energy Carolinas
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
RA-16-0032
Download: ML16271A329 (5)

Text

{_~ DUKE John Elnitsky 526 South Church Street ENERGY. Charlotte, NC 28202 Mailing Address:

Mail Code EC07H I P.O. Box 1006 Charlotte, NC 28201-1006 704-382-4371 10 CFR 50.46(a)(3)

Serial: RA-16-0032 September 22, 2016 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 CATAWBA NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-413 AND 50-414 /RENEWED LICENSE NOS. NPF-35 AND NPF-52 MCGUIRE NUCLEAR STATION, UNITS 1AND2 DOCKET NOS. 50-369 AND 50-370 I RENEWED LICENSE NOS. NPF-9 AND NPF-17

SUBJECT:

DUKE ENERGY Regulatory Commitment Change Related to Loss of Coolant Accident Reanalysis to Address Fuel Pellet Thermal Conductivity Degradation

References:

1. Letter from Duke Energy (David C. Culp) to USNRC (Document Control Desk), "Response to Information Request Pursuant to 10 CFR 50.54(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 and 30-Day Report Pursuant to 10 CFR 50.46, Changes to or Errors in an Evaluation Model," dated, March 16, 2012(ML12079A180)

In Reference 1, Duke Energy Carolinas, LLC (Duke Energy) submitted a report describing a significant error identified in the emergency core cooling system (ECCS) evaluation model , and an estimate of the effect of the error on the predicted peak cladding temperature (PCT) for Catawba Nuclear Station (CNS) Units 1 and 2, and McGuire Nuclear Station (MNS) Units 1 and

2. This report was submitted pursuant to 10 CFR 50.46(a)(3), and contained a regulatory commitment to perform a Large Break Loss of Coolant Accident (LBLOCA) reanalysis, accounting for the effects of fuel pellet thermal conductivity degradation (TCD) and accommodates the ongoing 10 CFR 50.46(c) rulemaking process, with a schedule of December 15, 2016 for submittal of the reanalysis (see Reference 1, Enclosure 2, page 1).

The original commitment and scheduled due date specified that consideration was included for 10 CFR 50.46 related rulemaking that was in-progress. Subsequent to the generation of the commitment, the NRC adjusted the target schedule for the rulemaking as described in

U.S. Nuclear Regulatory Commission RA-16-0032 Page 2 COMSECY-13-0006, dated March 4, 2013(ML13050A167), and the Commissioner's approval memorandum dated May 9, 2013(ML13129A401). At present, the 10 CFR 50.46(c) rulemaking package and draft final rule language is with the NRC Commissioners for approval per SECY-16-0033, dated March 16, 2016(ML15238A933).

WCAP-17642-P, "Westinghouse Performance Analysis and Design Model (PADS)," has been submitted to the NRC as a revised fuel performance methodology that includes the effects of TCD. WCAP-16996-P, "Realistic LOCA Evaluation Methodology Applied to Full Spectrum of Break Sizes (Full Spectrum LOCA Methodology)," was submitted to the NRC as a revised LOCA Evaluation Model. Both WCAP-17642-P and WCAP-16996-P are currently undergoing NRC staff review. A supplement to WCAP-16996-P to include changes associated with the forthcoming 10 CFR 50.46c rulemaking is expected to be submitted for NRC review and approval at some point after the effective date for 10 CFR 50.46(c).

The date for the submittal of the analyses is projected based upon the following milestones needed to perform a revised licensing basis LBLOCA analysis with an NRC approved ECCS Evaluation Model that explicitly accounts for TCD:

1) NRC approval of WCAP-17642-P, a fuel performance analysis methodology that includes the effects of TCD.

2) NRC approval of WCAP-16996-P, and any required Supplements thereto, a LBLOCA Evaluation Model that includes the effects of TCD and accommodates the ongoing 10 CFR 50.46(c) rulemaking process.

The changed due date is structured such that the Catawba and McGuire-specific work risk due to potential changes to the final rule and/or vendor analysis methods are limited to the extent possible. The duration allows for time to perform analysis scoping and input selection with time to consider margin optimization. This commitment supersedes that made in Reference 1.

The revised commitment per this letter:

Duke Energy will submit to the NRC for review LBLOCA analyses for Catawba and McGuire that apply NRG-approved methods that include the effects of fuel thermal conductivity degradation (TCD). The revised due date for this commitment is 24 months from the latest NRC approval ofWCAP-17642-P, WCAP-16996-P, and any supplements that are needed for analysis related to the new 10 CFR 50.46(c) rule.

If you should have any questions regarding this submittal, or require additional information, please contact Art Zaremba, Manager- Nuclear Fleet Licensing, at 980-373-2062.

I declare under penalty of perjury that the foregoing is true and correct. Executed on 09/22/2016.

U.S. Nuclear Regulatory Commission RA-16-0032 Page 3 Joh Elnitsky enior Vice President - Nuclear Engineering

Enclosure:

U.S. Nuclear Regulatory Commission RA-16-0032 Page4 xc:

C. Haney, Regional Administrator U.S. Nuclear Regulatory Commission - Region II Marquis One Tower 245 Peachtree Center Ave., NE Suite 1200 Atlanta, GA 30303-1257 Michael D. Orenak, Project Manager (Catawba)

U.S. Nuclear Regulatory Commission One White Flint North 11555 Rockville Pike Rockville, MD 20852-2738 G. Edward Miller, Project Manager (McGuire)

V. Sreenivas (temporary Project Manager)

U.S. Nuclear Regulatory Commission One White Flint North, Mail Stop 8 G9A 11555 Rockville Pike Rockville, MD 20852-2738 G.A. Hutto, Ill NRC Senior Resident Inspector Catawba Nuclear Station John Zeiler NRC Senior Resident Inspector McGuire Nuclear Station Chair - North Carolina Utilities Commission P.O. Box 29510 Raleigh, NC 27626-0510

U.S. Nuclear Regulatory Commission RA-16-0032 Enclosure Original Regulatory Commitment and Schedule "Before December 15, 2016, Duke Energy will submit to the NRG for review and approval a LBLOGA analysis that applies NRG-approved EGGS Evaluation Model that includes the effects of fuel thermal conductivity degradation."

Revised Regulatory Commitment and Schedule "Duke Energy will submit to the NRG for review and approval a LBLOGA analysis for Catawba and McGuire that apply NRG-approved methods that include the effects of fuel thermal conductivity degradation (TGD). The revised due date for this commitment is 24 months from the latest NRC approval of WCAP-17642-P, WCAP-16996-P, and any supplements that are needed for analysis related to the new 10 CFR 50.46(c) rule."