CP-201800311, ECCS Re-Analysis Schedule

ECCS Re-Analysis Schedule

ML18213A170
Person / Time
Site:	Comanche Peak
Issue date:	07/19/2018
From:	Sewell S Vistra Energy
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CP-201800311, TXX-18035
Download: ML18213A170 (3)

Text

ENERGY "f(* energy f!Alrxu I m Luminant Steven K. Sewell Senior Director, Engineering & Regulatory Affairs Luminant P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 o 254.897.6113 Ref 10 CFR 50.46{a)(3)(ii)

CP-201800311 TXX-18035 U.S. Nuclear Regulatory Commission ATIN: Document Control Desk Washington, DC 20555-0001 7/19/2018

SUBJECT:

COMANCHE PEAK NUCLEAR POWER PLANT DOCKET NOS. 50-445 AND 50-446 ECCS RE-ANALYSIS SCHEDULE

REFERENCES:

1. Luminant Power Letter Logged TXX-15009, from Rafael Flores to the NRC dated January 28, 2015, "ECCS RE-ANALYSIS SCHEDULE"

Dear Sir or Madam:

Via Reference 1 Vistra Operations Company LLC (Vistra OpCo) provided information relative to the ongoing re-analysis of a large break loss-of-coolant accident (LBLOCA) analysis which includes the effects of fuel thermal conductivity degradation, revised heat transfer multiplier distributions, changes to grid blockage ratio and porosity, and correct application of the burst strain in the scheduled reanalysis. The schedule presented therein was based, in part, on the Nuclear Regulatory Commission (NRC) efforts to revise 10CFR50.46 for performance-based emergency core cooling systems cladding acceptance criteria (Federal Register Notice 79FR16106) and Westinghouse efforts for development of an emergency core cooling system (ECCS) code that would satisfy the proposed rulemaking.

Reference 1 contained two commitments:

Commitment Number 4496966 - Vistra OpCo will submit to the NRC, for review and approval, a LBLOCA analysis which applies NRC-approved methods that include the effects of fuel pellet thermal conductivity by June 15, 2018 or 24 months from the effective date of the proposed 10CFR50.46 rule implementation, whichever occurs first.

6555 SIERRA DRIVE IRVING, TEXAS 75039 0214-812-4600 VISTRAENERGY.COM

TXX-18035 Page 2 of 2 Commitment Number 4829670 -Vistra OpCo will include the revised heat transfer multiplier distributions, changes to the grid blockage ratio and porosity, and correct application of the burst strain in the scheduled reanalysis.

The ongoing analyses are presently expected to be completed during the first quarter of 2019 with submittal to the NRC in the following quarter. That effort is necessarily independent of potential regulatory action in the form of revision of lOCFRS0.46. Commitment Number 4496966 is being revised accordingly.

This communication contains no new commitments regarding CPNPP Units 1 and 2. The revision of commitment number 4496966 is provided in Attachment 1 of this letter.

Should you have any questions, please contact Ken Vehstedt at {254) 897-6296.

Sincerely, Sz:c-,[c~

Steven K. Sewell Revised Commitment c- Kriss Kennedy, Region IV Margaret Watford O'Banion, NRR Resident Inspectors, Comanche Peak to TXX-18035 Page 1 of 1 Revised Commitment Commitment Number 4496966 Commitment Description Vistra OpCo will submit to the NRC, for review and approval, a LBLOCA analysis which applies NRC-approved methods that include the effects of fuel pellet thermal conductivity.

Scheduled Completion Date June 30, 2019 Status/ Comments Open/ Commitment was originally identified in letter dated TXX-15009 and updated by letterTXX-18035