CP-202200205, (CPNPP) - License Amendment Request (LAR) 20-006 Application to Revise Technical Specifications to Adopt Risk Informed Completion Times, TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - Rtstf.

(CPNPP) - License Amendment Request (LAR)20-006 Application to Revise Technical Specifications to Adopt Risk Informed Completion Times, TSTF-505, Revision 2, Provide Risk-Informed Extended Completion Times - Rtstf.

ML22132A119
Person / Time
Site:	Comanche Peak
Issue date:	05/12/2022
From:	Thomas McCool Luminant, Vistra Operations Company
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
CP-202200205, TXX-22043
Download: ML22132A119 (3)

Text

m Thomas P. McCool Site Vice President Comanche Peak Nuclear Power Plant (Vistra Operations Company LLC)

Luminant P.O. Box 1002 6322 North FM 56 Glen Rose, TX 76043 T 254 .897 .6042 CP-202200205 TXX-22043 May 12, 2022 U.S. Nuclear Regulatory Commission Ref 10 CFR50.90 ATIN: Document Control Desk 10 CFR 50.91(b)(l)

Washington, DC 20555-0001

Subject:

Comanche Peak Nuclear Power Plant (CPNPP)

Docket Nos. 50-445 and 50-446 LICENSE AMENDMENT REQUEST (LAR)20-006 APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT RISK INFORMED COMPLETION TIMES, TSTF-505, REVISION 2, "PROVIDE RISK-INFORMED EXTENDED COMPLETION TIMES- RITSTF INITIATIVE 4b" CLARIFICATION

Reference:

1. Letter TXX-21046 from Thomas P. McCool to the NRC, License Amendment Request (LAR)20-006, APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT RISK INFORMED COMPLETION TIMES, TSTF-505, REVISION 2, "PROVIDE RISK-INFORMED EXTENDED COMPLETION TIMES- RITSTF INITIATIVE 4b," dated May 11, 2021 (ADAMS Accession No. ML21131A233)

2. Letter TXX-21093 from Thomas P. McCool to the NRC, Supplement to License Amendment Request (LAR)20-006 APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT RISK INFORMED COMPLETION TIMES, TSTF-505, REVISION 2, "PROVIDE RISK-INFORMED EXTENDED COMPLETION TIMES- RITSTF INITIATIVE 4b, dated July 13, 2021 (ADAMS Accession No. ML21194A078)

3. Letter TXX-22002 from Thomas P. McCool to the NRC, Second Supplement to License Amendment Request (LAR)20-006 APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT RISK INFORMED COMPLETION TIMES, TSTF-505, REVISION 2, "PROVIDE RISK-INFORMED EXTENDED COMPLETION TIMES - RITSTF INITIATIVE 4b, dated February 17, 2022 (ADAMS Accession No. ML22048B490)

4. E-mail to the Licensee (Vistra Operations Company LLC (Vistra OpCo)) from the Nuclear Regulatory Commission, "Comanche Peak - Request for Additional Information - Request to Adopt TSTF-505 Revision 2," dated March 23, 2022 (ADAMS Accession No. ML22083A026)

TXX-22043 Page 2 of 3

5. Letter TXX-22029 from Thomas P. McCool to the NRC, License Amendment Request (LAR)20-006 APPLICATION TO REVISE TECHNICAL SPECIFICATIONS TO ADOPT RISK INFORMED COMPLETION TIMES, TSTF-505, REVISION 2, "PROVIDE RISK-INFORMED EXTENDED COMPLETION TIMES- RITSTF INITIATIVE 4b" REQUEST FOR ADDITIONAL INFORMATION (RAI), dated March 29, 2022 (ADAMS Accession No. ML22088A299)

Dear Sir or Madam:

Pursuant to 10 CFR 50.90 and 10 CFR 50.91, Vistra Operations Company LLC (Vistra OpCo) is providing a clarifying communication for an amendment to the Comanche Peak Nuclear Power Plant (CPNPP) Unit 1 and Unit 2 Technical Specifications made by Reference 1, Reference 2, Reference 3, and Reference 5.

Vistra OpCo requests adoption of Risk Informed Completion Times in accordance with TSTF-505, Revision 2, "Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4b", (ADAMS Accession No. ML18183A493).

This response provides the following clarifying statement; The baseline values of the CDF and LERF for each unit, as presented in Enclosure 5 Table 1 of the Comanche Peak response of March 29, 2022 (TXX-22029, ML22088A299), are accurate and reflect the current Models of Record.

The information presented on page 32 of 88 of the Executive Summary of the Comanche Peak response of February 17, 2022 (TXX-22002, ML22048B490) was a quick sensitivity case performed during the audit to address a question during the audit discussions. The focus of the sensitivity run was on the delta-CDF attributable to a change in the HEP floor value selected for use in the Fire PRA modeling.

An existing one-top (integrated) model with a plant-specific work week alignment (or plant configuration

- which h*ain of a support system is aligned, etc.) was used for the sensitivity run which was known to be a very "high-CDF" alignment. This particular system alignment accentuates the importance of the fire, resulting in a high CDF. (In practice, this alignment would not be used as-is without the implementation of appropriate RMAs.) The focus of the sensitivity run was on the delta-CDF, not on the actual values of CDF.

While the delta-CDF supporting the HEP floor sensitivity study remains appropriate, actual CDFs from this model will not be consistent with the baseline CDFs, as the models represent two different plant configurations. Thus, it is inappropriate to compare the values.

In accordance with 10 CFR 50.91(b)(l), a copy of this correspondence regarding the proposed license amendment is being forwarded to the State of Texas.

Vistra OpCo has determined that this correspondence does not change the No Significant Hazards Consideration submitted in Reference 1.

This communication contains no new commitments regarding CPNPP Units 1 and 2.

Should you have any questions, please contact Garry Struble at (254) 897-6628 or Garry.Struble@luminant.com.

TXX-22043 Page 3 of 3 I state under penalty of perjury that the foregoing is true and correct.

Executed on May 12, 2022.

Sincerely, c (email) - Scott Morris, Region IV [Scott.Morris@nrc.gov]

Dennis Galvin, NRR [Dennis.Galvin@nrc.gov]

John Ellegood, Senior Resident Inspector, CPNPP Uohn.Ellegood@nrc.gov]

Neil Day, Resident Inspector, CPNPP [Neil.Day@nrc.gov]

Mr. Robert Free [robert.free@dshs.state.tx.us]

Environmental Monitoring & Emergency Response Manager Texas Department of State Health Services Mail Code 1986 P.O. Box 149347 Austin, TX 78714-9347